diff --git a/lam/docs/devel/modules-specification.htm b/lam/docs/devel/modules-specification.htm
index 2ac70e0c..3f3e2c77 100644
--- a/lam/docs/devel/modules-specification.htm
+++ b/lam/docs/devel/modules-specification.htm
@@ -747,18 +747,17 @@ is needed t interact with the user.<br>
 <br>
 This function processes user input. It checks user input. It also
 saves changes in attributes.<br>
-This functions can return two different variables. When 0 is returned
-everything is ok. If it
-returns an array the array contains status<br>
-messages. First index is the attribute which has triggered a message.
-Second index is an array containing status message arrays.<br>
-This function must reset $this-&gt;triggered_messages when it wants to
-display
-status messages. This can be done with $this-&gt;triggered_messages =
-array();<br>
+It may
+return an array which contains status messages. Each entry is an array
+containing the status message parameters.<br>
 <span style="font-weight: bold;">$post</span> is the $_POST
 array.<br>
 <br>
+<span style="font-weight: bold; text-decoration: underline;">Example:</span><br>
+<br>
+return array(0 =&gt; array('ERROR', 'Invalid input!', 'This is not
+allowed here.'));<br>
+<br>
 <br>
 <h3>2.2.14. process_*<br>
 </h3>
diff --git a/lam/lib/modules.inc b/lam/lib/modules.inc
index e682dca4..7921c948 100644
--- a/lam/lib/modules.inc
+++ b/lam/lib/modules.inc
@@ -861,8 +861,8 @@ class accountContainer {
 				}
 			}
 		}
-		// go to subpage of current module
 		if (!$errorsOccured) {
+			// go to subpage of current module
 			$postKeys = array_keys($post);
 			for ($p = 0; $p < sizeof($postKeys); $p++) {
 				if (is_string($postKeys[$p]) && (strpos($postKeys[$p], 'form_subpage_' . $this->order[$this->current_page]) === 0)) {
@@ -873,24 +873,26 @@ class accountContainer {
 					}
 				}
 			}
-		}
-		if (is_int($result) || !$errorsOccured) {  // numeric return value means to change to another module
+			// change module page if requested
 			if ($post['form_main_main']) {
 				$this->current_page = 0;
 				$this->subpage='attributes';
 			}
-			else for ($i=1; $i<count($this->order); $i++ )
-				if (isset($post['form_main_'.$this->order[$i]])) {
-					if ($this->module[$this->order[$i]]->module_ready()) {
-						$this->current_page = $i;
-						$this->subpage='attributes';
-					}
-					else {
-						StatusMessage('ERROR', _('The module %s is not yet ready.'),
-							_('Please enter the account information on the other pages first.'),
-							array($this->module[$this->order[$i]]->get_alias()));
+			else {
+				for ($i=1; $i<count($this->order); $i++ ) {
+					if (isset($post['form_main_'.$this->order[$i]])) {
+						if ($this->module[$this->order[$i]]->module_ready()) {
+							$this->current_page = $i;
+							$this->subpage='attributes';
+						}
+						else {
+							StatusMessage('ERROR', _('The module %s is not yet ready.'),
+								_('Please enter the account information on the other pages first.'),
+								array($this->module[$this->order[$i]]->get_alias()));
+						}
 					}
 				}
+			}
 		}
 		// Write HTML-Code
 		echo $_SESSION['header'];
diff --git a/lam/lib/modules/account.inc b/lam/lib/modules/account.inc
index 4cff8571..d5c2819b 100644
--- a/lam/lib/modules/account.inc
+++ b/lam/lib/modules/account.inc
@@ -183,7 +183,12 @@ class account extends baseModule {
 		return $return;
 	}
 
-	/* Write variables into object and do some regexp checks
+	/**
+	* Processes user input of the primary module page.
+	* It checks if all input values are correct and updates the associated LDAP attributes.
+	*
+	* @param array $post HTTP-POST values
+	* @return array list of info/error messages
 	*/
 	function process_attributes(&$post) {
 		// Load attributes
@@ -195,7 +200,6 @@ class account extends baseModule {
 			if (!get_preg($this->attributes['uid'][0], '!upper')) $triggered_messages['uid'][] = $this->messages['uid'][2];
 			if (!get_preg($this->attributes['uid'][0], 'username')) $triggered_messages['uid'][] = $this->messages['uid'][3];
 		}
-		return 0;
 	}
 
 	/* This function will create the html-page
diff --git a/lam/lib/modules/ieee802device.inc b/lam/lib/modules/ieee802device.inc
index 84225b4f..e5c93532 100644
--- a/lam/lib/modules/ieee802device.inc
+++ b/lam/lib/modules/ieee802device.inc
@@ -157,9 +157,11 @@ class ieee802Device extends baseModule {
 	}
 
 	/**
-	* Write variables into object and do some regex checks
+	* Processes user input of the primary module page.
+	* It checks if all input values are correct and updates the associated LDAP attributes.
 	*
 	* @param array $post HTTP-POST values
+	* @return array list of info/error messages
 	*/
 	function process_attributes(&$post) {
 		$this->triggered_messages = array();
diff --git a/lam/lib/modules/inetLocalMailRecipient.inc b/lam/lib/modules/inetLocalMailRecipient.inc
index 62e129cb..ad1d42ef 100644
--- a/lam/lib/modules/inetLocalMailRecipient.inc
+++ b/lam/lib/modules/inetLocalMailRecipient.inc
@@ -219,9 +219,11 @@ class inetLocalMailRecipient extends baseModule {
 	}
 
 	/**
-	* Write variables into object and do some regex checks
+	* Processes user input of the primary module page.
+	* It checks if all input values are correct and updates the associated LDAP attributes.
 	*
 	* @param array $post HTTP-POST values
+	* @return array list of info/error messages
 	*/
 	function process_attributes(&$post) {
 		$this->triggered_messages = array();
@@ -286,7 +288,6 @@ class inetLocalMailRecipient extends baseModule {
 		}
 		else {
 			$this->inputCorrect = true;
-			return 0;
 		}
 	}
 
diff --git a/lam/lib/modules/inetOrgPerson.inc b/lam/lib/modules/inetOrgPerson.inc
index 4931a263..2edfe40f 100644
--- a/lam/lib/modules/inetOrgPerson.inc
+++ b/lam/lib/modules/inetOrgPerson.inc
@@ -413,6 +413,13 @@ class inetOrgPerson extends baseModule {
 		return $return;
 	}
 
+	/**
+	* Processes user input of the primary module page.
+	* It checks if all input values are correct and updates the associated LDAP attributes.
+	*
+	* @param array $post HTTP-POST values
+	* @return array list of info/error messages
+	*/
 	function process_attributes(&$post) {
 		// Load attributes
 		$this->attributes['description'][0] = $post['description'];
@@ -498,8 +505,6 @@ class inetOrgPerson extends baseModule {
 		}
 		// Return error-messages
 		if (is_array($triggered_messages)) return $triggered_messages;
-		if ($post['changepass']) return 'password';
-		return 0;
 		}
 
 	/* This function will create the html-page
diff --git a/lam/lib/modules/kolabUser.inc b/lam/lib/modules/kolabUser.inc
index 160a78f6..7f401ade 100644
--- a/lam/lib/modules/kolabUser.inc
+++ b/lam/lib/modules/kolabUser.inc
@@ -433,9 +433,11 @@ class kolabUser extends baseModule {
 	}
 
 	/**
-	* Write variables into object and do some regex checks
+	* Processes user input of the primary module page.
+	* It checks if all input values are correct and updates the associated LDAP attributes.
 	*
 	* @param array $post HTTP-POST values
+	* @return array list of info/error messages
 	*/
 	function process_attributes(&$post) {
 		if ($post['form_subpage_kolabUser_deleteUser_open'])  return;
@@ -582,7 +584,6 @@ class kolabUser extends baseModule {
 		}
 		else {
 			$this->inputCorrect = true;
-			return 0;
 		}
 	}
 
diff --git a/lam/lib/modules/nisMailAlias.inc b/lam/lib/modules/nisMailAlias.inc
index cebf7677..1282bd2f 100644
--- a/lam/lib/modules/nisMailAlias.inc
+++ b/lam/lib/modules/nisMailAlias.inc
@@ -191,9 +191,11 @@ class nisMailAlias extends baseModule {
 	}
 
 	/**
-	* Write variables into object and do some regex checks
+	* Processes user input of the primary module page.
+	* It checks if all input values are correct and updates the associated LDAP attributes.
 	*
 	* @param array $post HTTP-POST values
+	* @return array list of info/error messages
 	*/
 	function process_attributes(&$post) {
 		$this->triggered_messages = array();
@@ -242,7 +244,6 @@ class nisMailAlias extends baseModule {
 		}
 		else {
 			$this->inputCorrect = true;
-			return 0;
 		}
 	}
 
diff --git a/lam/lib/modules/posixAccount.inc b/lam/lib/modules/posixAccount.inc
index 02b3dd3a..6ffac0b6 100644
--- a/lam/lib/modules/posixAccount.inc
+++ b/lam/lib/modules/posixAccount.inc
@@ -615,7 +615,12 @@ class posixAccount extends baseModule {
 		return $return;
 	}
 
-	/* Write variables into object and do some regexp checks
+	/**
+	* Processes user input of the primary module page.
+	* It checks if all input values are correct and updates the associated LDAP attributes.
+	*
+	* @param array $post HTTP-POST values
+	* @return array list of info/error messages
 	*/
 	function process_attributes(&$post) {
 		$triggered_messages = array();
@@ -828,31 +833,31 @@ class posixAccount extends baseModule {
 			return $triggered_messages;
 		}
 		else $this->triggered_messages = array();
-		return 0;
-	}
-
-	/* Write variables into object and do some regexp checks
-	*/
-	function process_group(&$post) {
-		do { // X-Or, only one if() can be true
-		if (isset($post['addgroups']) && isset($post['addgroups_button'])) { // Add groups to list
-		// Add new group
-		$this->groups = @array_merge($this->groups, $post['addgroups']);
-		break;
-		}
-		if (isset($post['removegroups']) && isset($post['removegroups_button'])) { // remove groups from list
-		$this->groups = array_delete($post['removegroups'], $this->groups);
-		break;
-		}
-		} while(0);
-	if (isset($post['addgroups_button']) || isset($post['removegroups_button'])) return 'group';
-	return 0;
 	}
 
 	/**
-	* Sets a new password.
+	* Processes user input of the group selection page.
+	* It checks if all input values are correct and updates the associated LDAP attributes.
 	*
-	* @param $post HTTP POST
+	* @param array $post HTTP-POST values
+	* @return array list of info/error messages
+	*/
+	function process_group(&$post) {
+		if (isset($post['addgroups']) && isset($post['addgroups_button'])) { // Add groups to list
+			// Add new group
+			$this->groups = @array_merge($this->groups, $post['addgroups']);
+		}
+		elseif (isset($post['removegroups']) && isset($post['removegroups_button'])) { // remove groups from list
+			$this->groups = array_delete($post['removegroups'], $this->groups);
+		}
+	}
+
+	/**
+	* Processes user input of the password page.
+	* It checks if all input values are correct and updates the associated LDAP attributes.
+	*
+	* @param array $post HTTP-POST values
+	* @return array list of info/error messages
 	*/
 	function process_password(&$post) {
 		if ($post['form_subpage_posixAccount_attributes_back']) return;
diff --git a/lam/lib/modules/posixGroup.inc b/lam/lib/modules/posixGroup.inc
index 551d8fdc..f6858afd 100644
--- a/lam/lib/modules/posixGroup.inc
+++ b/lam/lib/modules/posixGroup.inc
@@ -529,7 +529,12 @@ class posixGroup extends baseModule {
 	}
 
 
-	/* Write variables into object and do some regexp checks
+	/**
+	* Processes user input of the primary module page.
+	* It checks if all input values are correct and updates the associated LDAP attributes.
+	*
+	* @param array $post HTTP-POST values
+	* @return array list of info/error messages
 	*/
 	function process_attributes(&$post) {
 		$this->attributes['description'][0] = $post['description'];
@@ -672,15 +677,15 @@ class posixGroup extends baseModule {
 			return $triggered_messages;
 		}
 		else $this->triggered_messages = array();
-		return 0;
 	}
 
 
 	/**
-	* Processes input data and adds or removes users from current group.
+	* Processes user input of the user selection page.
+	* It checks if all input values are correct and updates the associated LDAP attributes.
 	*
-	* @param array $post HTTP-POST
-	* @return string name of next page
+	* @param array $post HTTP-POST values
+	* @return array list of info/error messages
 	*/
 	function process_user(&$post) {
 		if (isset($post['addusers']) && isset($post['addusers_button'])) { // Add users to list
@@ -696,14 +701,15 @@ class posixGroup extends baseModule {
 		elseif (isset($post['removeusers']) && isset($post['removeusers_button'])) { // remove users from list
 			$this->attributes['memberUid'] = array_delete($post['removeusers'], $this->attributes['memberUid']);
 		}
-		return 0;
 	}
 
 
 	/**
-	* Sets a new password.
+	* Processes user input of the password page.
+	* It checks if all input values are correct and updates the associated LDAP attributes.
 	*
-	* @param $post HTTP POST
+	* @param array $post HTTP-POST values
+	* @return array list of info/error messages
 	*/
 	function process_password(&$post) {
 		if ($post['form_subpage_posixGroup_attributes_back']) return;
diff --git a/lam/lib/modules/quota.inc b/lam/lib/modules/quota.inc
index c0a12cfe..89ebcb2c 100644
--- a/lam/lib/modules/quota.inc
+++ b/lam/lib/modules/quota.inc
@@ -272,7 +272,12 @@ class quota extends baseModule {
 		return $return;
 		}
 
-	/* Write variables into object and do some regexp checks
+	/**
+	* Processes user input of the primary module page.
+	* It checks if all input values are correct and updates the associated LDAP attributes.
+	*
+	* @param array $post HTTP-POST values
+	* @return array list of info/error messages
 	*/
 	function process_attributes(&$post) {
 		// Write all general values into $account_new
@@ -304,8 +309,6 @@ class quota extends baseModule {
 			return $triggered_messages;
 		}
 		else $this->triggered_messages = array();
-		// Go to additional group page when no error did ocour and button was pressed
-		return 0;
 		}
 
 	/* This function will create the html-page
diff --git a/lam/lib/modules/sambaAccount.inc b/lam/lib/modules/sambaAccount.inc
index b78d38b7..869c85b5 100644
--- a/lam/lib/modules/sambaAccount.inc
+++ b/lam/lib/modules/sambaAccount.inc
@@ -493,7 +493,12 @@ class sambaAccount extends baseModule {
 		return $return;
 		}
 
-	/* Write variables into object and do some regexp checks
+	/**
+	* Processes user input of the primary module page.
+	* It checks if all input values are correct and updates the associated LDAP attributes.
+	*
+	* @param array $post HTTP-POST values
+	* @return array list of info/error messages
 	*/
 	function process_attributes(&$post) {
 		$this->attributes['domain'][0] = $post['domain'];
@@ -626,10 +631,14 @@ class sambaAccount extends baseModule {
 			return $triggered_messages;
 		}
 		else $this->triggered_messages = array();
-		return 0;
-		}
+	}
 
-	/* Write variables into object and do some regexp checks
+	/**
+	* Processes user input of the workstation selection page.
+	* It checks if all input values are correct and updates the associated LDAP attributes.
+	*
+	* @param array $post HTTP-POST values
+	* @return array list of info/error messages
 	*/
 	function process_userWorkstations(&$post) {
 		// Load attributes
@@ -672,7 +681,6 @@ class sambaAccount extends baseModule {
 				}
 			}
 		}
-		return 0;
 	}
 
 	/* This function will create the html-page
diff --git a/lam/lib/modules/sambaGroupMapping.inc b/lam/lib/modules/sambaGroupMapping.inc
index 428619a7..04f5fa3a 100644
--- a/lam/lib/modules/sambaGroupMapping.inc
+++ b/lam/lib/modules/sambaGroupMapping.inc
@@ -386,7 +386,12 @@ class sambaGroupMapping extends baseModule {
 		}
 
 
-	/* Write variables into object and do some regexp checks
+	/**
+	* Processes user input of the primary module page.
+	* It checks if all input values are correct and updates the associated LDAP attributes.
+	*
+	* @param array $post HTTP-POST values
+	* @return array list of info/error messages
 	*/
 	function process_attributes(&$post) {
 		// Save attributes
@@ -425,8 +430,7 @@ class sambaGroupMapping extends baseModule {
 			return $triggered_messages;
 		}
 		else $this->triggered_messages = array();
-		return 0;
-		}
+	}
 
 
 	/* This function returns an array with 3 entries:
diff --git a/lam/lib/modules/sambaSamAccount.inc b/lam/lib/modules/sambaSamAccount.inc
index 938702bd..536dc307 100644
--- a/lam/lib/modules/sambaSamAccount.inc
+++ b/lam/lib/modules/sambaSamAccount.inc
@@ -486,7 +486,12 @@ class sambaSamAccount extends baseModule {
 		return $return;
 	}
 
-	/* Write variables into object and do some regexp checks
+	/**
+	* Processes user input of the primary module page.
+	* It checks if all input values are correct and updates the associated LDAP attributes.
+	*
+	* @param array $post HTTP-POST values
+	* @return array list of info/error messages
 	*/
 	function process_attributes(&$post) {
 		// Save attributes
@@ -635,62 +640,64 @@ class sambaSamAccount extends baseModule {
 			return $triggered_messages;
 		}
 		else $this->triggered_messages = array();
-		return 0;
 	}
 
-	/* Write variables into object and do some regexp checks
+	/**
+	* Processes user input of the primary module page.
+	* It checks if all input values are correct and updates the associated LDAP attributes.
+	*
+	* @param array $post HTTP-POST values
+	* @return array list of info/error messages
 	*/
 	function process_sambaUserWorkstations(&$post) {
 		// Load attributes
 		if ($_SESSION[$this->base]->type=='user') {
-			do { // X-Or, only one if() can be true
-				if (isset($post['availableSambaUserWorkstations']) && isset($post['sambaUserWorkstations_add'])) { // Add workstations to list
-					$temp = str_replace(' ', '', $this->attributes['sambaUserWorkstations'][0]);
-					$workstations = explode (',', $temp);
-					for ($i=0; $i<count($workstations); $i++)
-						if ($workstations[$i]=='') unset($workstations[$i]);
-					$workstations = array_values($workstations);
-					// Add new // Add workstations
-					$workstations = array_merge($workstations, $post['availableSambaUserWorkstations']);
-					// remove doubles
-					$workstations = array_flip($workstations);
-					array_unique($workstations);
-					$workstations = array_flip($workstations);
-					// sort workstations
-					sort($workstations);
-					// Recreate workstation string
-					$this->attributes['sambaUserWorkstations'][0] = $workstations[0];
-					for ($i=1; $i<count($workstations); $i++) {
-						$this->attributes['sambaUserWorkstations'][0] = $this->attributes['sambaUserWorkstations'][0] . "," . $workstations[$i];
-						}
-					break;
+			if (isset($post['availableSambaUserWorkstations']) && isset($post['sambaUserWorkstations_add'])) { // Add workstations to list
+				$temp = str_replace(' ', '', $this->attributes['sambaUserWorkstations'][0]);
+				$workstations = explode (',', $temp);
+				for ($i=0; $i<count($workstations); $i++) {
+					if ($workstations[$i]=='') unset($workstations[$i]);
+				}
+				$workstations = array_values($workstations);
+				// Add new // Add workstations
+				$workstations = array_merge($workstations, $post['availableSambaUserWorkstations']);
+				// remove doubles
+				$workstations = array_flip($workstations);
+				array_unique($workstations);
+				$workstations = array_flip($workstations);
+				// sort workstations
+				sort($workstations);
+				// Recreate workstation string
+				$this->attributes['sambaUserWorkstations'][0] = $workstations[0];
+				for ($i=1; $i<count($workstations); $i++) {
+					$this->attributes['sambaUserWorkstations'][0] = $this->attributes['sambaUserWorkstations'][0] . "," . $workstations[$i];
 					}
-				if (isset($post['sambaUserWorkstations']) && isset($post['sambaUserWorkstations_remove'])) { // remove // Add workstations from list
-					// Put all workstations in array
-					$temp = str_replace(' ', '', $this->attributes['sambaUserWorkstations'][0]);
-					$workstations = explode (',', $temp);
-					for ($i=0; $i<count($workstations); $i++)
-						if ($workstations[$i]=='') unset($workstations[$i]);
-					$workstations = array_values($workstations);
-					// Remove unwanted workstations from array
-					$workstations = array_delete($post['sambaUserWorkstations'], $workstations);
-					// Recreate workstation string
-					$this->attributes['sambaUserWorkstations'][0] = $workstations[0];
-					for ($i=1; $i<count($workstations); $i++) {
-						$this->attributes['sambaUserWorkstations'][0] = $this->attributes['sambaUserWorkstations'][0] . "," . $workstations[$i];
-						}
-					break;
-					}
-				} while(0);
+				}
+			elseif (isset($post['sambaUserWorkstations']) && isset($post['sambaUserWorkstations_remove'])) { // remove // Add workstations from list
+				// Put all workstations in array
+				$temp = str_replace(' ', '', $this->attributes['sambaUserWorkstations'][0]);
+				$workstations = explode (',', $temp);
+				for ($i=0; $i<count($workstations); $i++) {
+					if ($workstations[$i]=='') unset($workstations[$i]);
+				}
+				$workstations = array_values($workstations);
+				// Remove unwanted workstations from array
+				$workstations = array_delete($post['sambaUserWorkstations'], $workstations);
+				// Recreate workstation string
+				$this->attributes['sambaUserWorkstations'][0] = $workstations[0];
+				for ($i=1; $i<count($workstations); $i++) {
+					$this->attributes['sambaUserWorkstations'][0] = $this->attributes['sambaUserWorkstations'][0] . "," . $workstations[$i];
+				}
 			}
-		return 0;
+		}
 	}
 
 	/**
-	* Save logon hours
+	* Processes user input of the logon hours page.
+	* It checks if all input values are correct and updates the associated LDAP attributes.
 	*
-	* @param array $post HTTP POST variables
-	* @return string next page name (attributes or logonHours)
+	* @param array $post HTTP-POST values
+	* @return array list of info/error messages
 	*/
 	function process_logonHours(&$post) {
 		if ($post['form_subpage_sambaSamAccount_attributes_abort']) return;
diff --git a/lam/lib/modules/shadowAccount.inc b/lam/lib/modules/shadowAccount.inc
index ce4a9ac9..37d34b6e 100644
--- a/lam/lib/modules/shadowAccount.inc
+++ b/lam/lib/modules/shadowAccount.inc
@@ -235,9 +235,11 @@ class shadowAccount extends baseModule {
 	}
 
 	/**
-	* Checks user input and saves it in LDAP attributes.
+	* Processes user input of the primary module page.
+	* It checks if all input values are correct and updates the associated LDAP attributes.
 	*
-	* @param array $post HTTP POST data
+	* @param array $post HTTP-POST values
+	* @return array list of info/error messages
 	*/
 	function process_attributes(&$post) {
 		// Load attributes
@@ -256,7 +258,6 @@ class shadowAccount extends baseModule {
 			return $triggered_messages;
 		}
 		else $this->triggered_messages = array();
-		return 0;
 	}
 
 	/**