diff --git a/core/css/multiselect.css b/core/css/multiselect.css
index 99f0e03933..31c8ef88eb 100644
--- a/core/css/multiselect.css
+++ b/core/css/multiselect.css
@@ -5,15 +5,25 @@
  ul.multiselectoptions {
  	background-color:#fff;
  	border:1px solid #ddd;
- 	border-bottom-left-radius:.5em;
- 	border-bottom-right-radius:.5em;
  	border-top:none;
  	box-shadow:0 1px 1px #ddd;
  	padding-top:.5em;
  	position:absolute;
+	max-height: 20em;
+	overflow-y: auto;
  	z-index:49;
  }
 
+ ul.multiselectoptions.down {
+ 	border-bottom-left-radius:.5em;
+ 	border-bottom-right-radius:.5em;
+ }
+
+ ul.multiselectoptions.up {
+ 	border-top-left-radius:.5em;
+ 	border-top-right-radius:.5em;
+ }
+
  ul.multiselectoptions>li {
  	overflow:hidden;
  	white-space:nowrap;
@@ -30,11 +40,20 @@
 
  div.multiselect.active {
  	background-color:#fff;
+ 	position:relative;
+ 	z-index:50;
+ }
+
+ div.multiselect.up {
+ 	border-top:0 none;
+ 	border-top-left-radius:0;
+ 	border-top-right-radius:0;
+ }
+
+ div.multiselect.down {
  	border-bottom:none;
  	border-bottom-left-radius:0;
  	border-bottom-right-radius:0;
- 	position:relative;
- 	z-index:50;
  }
 
  div.multiselect>span:first-child {
diff --git a/core/js/multiselect.js b/core/js/multiselect.js
index c4fd74b047..623c6e0f7e 100644
--- a/core/js/multiselect.js
+++ b/core/js/multiselect.js
@@ -1,20 +1,44 @@
+/**
+ * @param 'createCallback' A function to be called when a new entry is created. Two arguments are supplied to this function:
+ *	The select element used and the value of the option. If the function returns false addition will be cancelled. If it returns
+ * 	anything else it will be used as the value of the newly added option.
+ * @param 'createText' The placeholder text for the create action.
+ * @param 'title' The title to show if no options are selected.
+ * @param 'checked' An array containing values for options that should be checked. Any options which are already selected will be added to this array.
+ * @param 'labels' The corresponding labels to show for the checked items.
+ * @param 'oncheck' Callback function which will be called when a checkbox/radiobutton is selected. If the function returns false the input will be unchecked.
+ * @param 'onuncheck' @see 'oncheck'.
+ * @param 'singleSelect' If true radiobuttons will be used instead of checkboxes. 
+ */
 (function( $ ){
 	var multiSelectId=-1;
-	$.fn.multiSelect=function(options){
+	$.fn.multiSelect=function(options) {
 		multiSelectId++;
 		var settings = {
 			'createCallback':false,
 			'createText':false,
+			'singleSelect':false,
+			'selectedFirst':false,
+			'sort':true,
 			'title':this.attr('title'),
 			'checked':[],
+			'labels':[],
 			'oncheck':false,
 			'onuncheck':false,
 			'minWidth': 'default;',
 		};
+		$(this).attr('data-msid', multiSelectId);
 		$.extend(settings,options);
-		$.each(this.children(),function(i,option){
-			if($(option).attr('selected') && settings.checked.indexOf($(option).val())==-1){
+		$.each(this.children(),function(i,option) {
+			// If the option is selected, but not in the checked array, add it.
+			if($(option).attr('selected') && settings.checked.indexOf($(option).val()) === -1) {
 				settings.checked.push($(option).val());
+				settings.labels.push($(option).text().trim());
+			}
+			// If the option is in the checked array but not selected, select it.
+			else if(settings.checked.indexOf($(option).val()) !== -1 && !$(option).attr('selected')) {
+				$(option).attr('selected', 'selected');
+				settings.labels.push($(option).text().trim());
 			}
 		});
 		var button=$('<div class="multiselect button"><span>'+settings.title+'</span><span>▾</span></div>');
@@ -24,24 +48,36 @@
 		button.selectedItems=[];
 		this.hide();
 		this.before(span);
-		if(settings.minWidth=='default'){
+		if(settings.minWidth=='default') {
 			settings.minWidth=button.width();
 		}
 		button.css('min-width',settings.minWidth);
 		settings.minOuterWidth=button.outerWidth()-2;
 		button.data('settings',settings);
-		if(settings.checked.length>0){
-			button.children('span').first().text(settings.checked.join(', '));
+
+		if(!settings.singleSelect && settings.checked.length>0) {
+			button.children('span').first().text(settings.labels.join(', '));
+		} else if(settings.singleSelect) {
+			button.children('span').first().text(this.find(':selected').text());
 		}
 
+		var self = this;
+		self.menuDirection = 'down';
 		button.click(function(event){
 			
 			var button=$(this);
-			if(button.parent().children('ul').length>0){
-				button.parent().children('ul').slideUp(400,function(){
-					button.parent().children('ul').remove();
-					button.removeClass('active');
-				});
+			if(button.parent().children('ul').length>0) {
+				if(self.menuDirection === 'down') {
+					button.parent().children('ul').slideUp(400,function() {
+						button.parent().children('ul').remove();
+						button.removeClass('active down');
+					});
+				} else {
+					button.parent().children('ul').fadeOut(400,function() {
+						button.parent().children('ul').remove();
+						button.removeClass('active up');
+					});
+				}
 				return;
 			}
 			var lists=$('ul.multiselectoptions');
@@ -54,49 +90,69 @@
 			event.stopPropagation();
 			var options=$(this).parent().next().children();
 			var list=$('<ul class="multiselectoptions"/>').hide().appendTo($(this).parent());
-			function createItem(element,checked){
+			var inputType = settings.singleSelect ? 'radio' : 'checkbox';
+			function createItem(element, checked){
 				element=$(element);
 				var item=element.val();
 				var id='ms'+multiSelectId+'-option-'+item;
-				var input=$('<input type="checkbox"/>');
+				var input=$('<input type="' + inputType + '"/>');
 				input.attr('id',id);
+				if(settings.singleSelect) {
+					input.attr('name', 'ms'+multiSelectId+'-option');
+				}
 				var label=$('<label/>');
 				label.attr('for',id);
-				label.text(item);
-				if(settings.checked.indexOf(item)!=-1 || checked){
-					input.attr('checked',true);
+				label.text(element.text() || item);
+				if(settings.checked.indexOf(item)!=-1 || checked) {
+					input.attr('checked', true);
 				}
 				if(checked){
-					settings.checked.push(item);
+					if(settings.singleSelect) {
+						settings.checked = [item];
+						settings.labels = [item];
+					} else {
+						settings.checked.push(item);
+						settings.labels.push(item);
+					}
 				}
 				input.change(function(){
-					var groupname=$(this).next().text();
-					if($(this).is(':checked')){
+					var value = $(this).attr('id').substring(String('ms'+multiSelectId+'-option').length+1);
+					var label = $(this).next().text().trim();
+					if($(this).is(':checked')) {
+						if(settings.singleSelect) {
+							settings.checked = [];
+							settings.labels = [];
+							$.each(self.find('option'), function() {
+								$(this).removeAttr('selected');
+							});
+						}
 						element.attr('selected','selected');
-						if(settings.oncheck){
-							if(settings.oncheck(groupname)===false){
+						if(typeof settings.oncheck === 'function') {
+							if(settings.oncheck(value)===false) {
 								$(this).attr('checked', false);
 								return;
 							}
 						}
-						settings.checked.push(groupname);
-					}else{
-						var index=settings.checked.indexOf(groupname);
+						settings.checked.push(value);
+						settings.labels.push(label);
+						$(this).parent().addClass('checked');
+					} else {
+						var index=settings.checked.indexOf(value);
 						element.attr('selected',null);
-						if(settings.onuncheck){
-							if(settings.onuncheck(groupname)===false){
+						if(typeof settings.onuncheck === 'function') {
+							if(settings.onuncheck(value)===false) {
 								$(this).attr('checked',true);
 								return;
 							}
 						}
+						$(this).parent().removeClass('checked');
 						settings.checked.splice(index,1);
+						settings.labels.splice(index,1);
 					}
 					var oldWidth=button.width();
-					if(settings.checked.length>0){
-						button.children('span').first().text(settings.checked.join(', '));
-					}else{
-						button.children('span').first().text(settings.title);
-					}
+					button.children('span').first().text(settings.labels.length > 0 
+						? settings.labels.join(', ')
+						: settings.title);
 					var newOuterWidth=Math.max((button.outerWidth()-2),settings.minOuterWidth)+'px';
 					var newWidth=Math.max(button.width(),settings.minWidth);
 					var pos=button.position();
@@ -110,6 +166,9 @@
 				});
 				var li=$('<li></li>');
 				li.append(input).append(label);
+				if(input.is(':checked')) {
+					li.addClass('checked');
+				}
 				return li;
 			}
 			$.each(options,function(index,item){
@@ -117,13 +176,13 @@
 			});
 			button.parent().data('preventHide',false);
 			if(settings.createText){
-				var li=$('<li>+ <em>'+settings.createText+'<em></li>');
+				var li=$('<li class="creator">+ <em>'+settings.createText+'<em></li>');
 				li.click(function(event){
 					li.empty();
 					var input=$('<input class="new">');
 					li.append(input);
 					input.focus();
-					input.css('width',button.width());
+					input.css('width',button.innerWidth());
 					button.parent().data('preventHide',true);
 					input.keypress(function(event) {
 						if(event.keyCode == 13) {
@@ -132,7 +191,7 @@
 							var value = $(this).val();
 							var exists = false;
 							$.each(options,function(index, item) {
-								if ($(item).val() == value) {
+								if ($(item).val() == value || $(item).text() == value) {
 									exists = true;
 									return false;
 								}
@@ -141,22 +200,39 @@
 								return false;
 							}
 							var li=$(this).parent();
+							var val = $(this).val()
+							var select=button.parent().next();
+							if(typeof settings.createCallback === 'function') {
+								var response = settings.createCallback(select, val);
+								if(response === false) {
+									return false;
+								} else if(typeof response !== 'undefined') {
+									val = response;
+								}
+							}
+							if(settings.singleSelect) {
+								$.each(select.find('option:selected'), function() {
+									$(this).removeAttr('selected');
+								});
+							}
 							$(this).remove();
 							li.text('+ '+settings.createText);
 							li.before(createItem(this));
-							var select=button.parent().next();
 							var option=$('<option selected="selected"/>');
-							option.attr('value',value);
-							option.text($(this).val());
+							option.text($(this).val()).val(val).attr('selected', 'selected');
 							select.append(option);
-							li.prev().children('input').trigger('click');
+							li.prev().children('input').prop('checked', true).trigger('change');
 							button.parent().data('preventHide',false);
-							if(settings.createCallback){
-								settings.createCallback($(this).val());
+							button.children('span').first().text(settings.labels.length > 0 
+								? settings.labels.join(', ')
+								: settings.title);
+							if(self.menuDirection === 'up') {
+								var list = li.parent();
+								list.css('top', list.position().top-li.outerHeight());
 							}
 						}
 					});
-					input.blur(function(){
+					input.blur(function() {
 						event.preventDefault();
 						event.stopPropagation();
 						$(this).remove();
@@ -168,21 +244,72 @@
 				});
 				list.append(li);
 			}
+			
+			var doSort = function(list, selector) {
+				var rows = list.find('li'+selector).get();
+
+				if(settings.sort) {
+					rows.sort(function(a, b) {
+						return $(a).text().toUpperCase().localeCompare($(b).text().toUpperCase());
+					});
+				}
+
+				$.each(rows, function(index, row) {
+					list.append(row);
+				});
+			};
+			if(settings.sort && settings.selectedFirst) {
+				doSort(list, '.checked');
+				doSort(list, ':not(.checked)');
+			} else if(settings.sort && !settings.selectedFirst) {
+				doSort(list, '');
+			}
+			list.append(list.find('li.creator'));
 			var pos=button.position();
-			list.css('top',pos.top+button.outerHeight()-5);
-			list.css('left',pos.left+3);
-			list.css('width',(button.outerWidth()-2)+'px');
-			list.slideDown();
-			list.click(function(event){
+			if($(document).height() > (button.offset().top+button.outerHeight() + list.children().length * button.height())
+				|| $(document).height()/2 > pos.top
+			) {
+				list.css({
+					top:pos.top+button.outerHeight()-5,
+					left:pos.left+3,
+					width:(button.outerWidth()-2)+'px',
+					'max-height':($(document).height()-(button.offset().top+button.outerHeight()+10))+'px'
+				});
+				list.addClass('down');
+				button.addClass('down');
+				list.slideDown();
+			} else {
+				list.css('max-height', $(document).height()-($(document).height()-(pos.top)+50)+'px');
+				list.css({
+					top:pos.top - list.height(),
+					left:pos.left+3,
+					width:(button.outerWidth()-2)+'px'
+					
+				});
+				list.detach().insertBefore($(this));
+				list.addClass('up');
+				button.addClass('up');
+				list.fadeIn();
+				self.menuDirection = 'up';
+			}
+			list.click(function(event) {
 				event.stopPropagation();
 			});
 		});
-		$(window).click(function(){
-			if(!button.parent().data('preventHide')){
-				button.parent().children('ul').slideUp(400,function(){
-					button.parent().children('ul').remove();
-					button.removeClass('active');
-				});
+		$(window).click(function() {
+			if(!button.parent().data('preventHide')) {
+				// How can I save the effect in a var?
+				if(self.menuDirection === 'down') {
+					button.parent().children('ul').slideUp(400,function() {
+						button.parent().children('ul').remove();
+						button.removeClass('active down');
+					});
+				} else {
+					button.parent().children('ul').fadeOut(400,function() {
+						button.parent().children('ul').remove();
+						button.removeClass('active up');
+					});
+				}
 			}
 		});
 		
diff --git a/settings/js/users.js b/settings/js/users.js
index b0e30feb80..fa6f058d92 100644
--- a/settings/js/users.js
+++ b/settings/js/users.js
@@ -177,9 +177,9 @@ var UserList = {
             } else {
                 checkHandeler = false;
             }
-            var addGroup = function (group) {
+            var addGroup = function (select, group) {
                 $('select[multiple]').each(function (index, element) {
-                    if ($(element).find('option[value="' + group + '"]').length == 0) {
+                    if ($(element).find('option[value="' + group + '"]').length === 0 && select.data('msid') !== $(element).data('msid')) {
                         $(element).append('<option value="' + group + '">' + group + '</option>');
                     }
                 })
@@ -193,6 +193,7 @@ var UserList = {
             element.multiSelect({
                 createCallback:addGroup,
                 createText:label,
+                selectedFirst:true,
                 checked:checked,
                 oncheck:checkHandeler,
                 onuncheck:checkHandeler,