Added a refresh method.

Refresh method can be used to reset size on a parent container state
change.

js/ui.multiselect.js

@@ -131,12 +131,34 @@ $.widget("ui.multiselect", {
 			return false;
 		});
 	},
+
+	refresh : function() {
+
+		// reset dimensions
+		this._setDimensions();
+
+	},
+
 	destroy: function() {
 		this.element.show();
 		this.container.remove();
 
 		$.Widget.prototype.destroy.apply(this, arguments);
 	},
+
+	_setDimensions : function() {
+
+		// set dimensions
+		this.container.width(this.element.width()+1);
+		this.selectedContainer.width(Math.floor(this.element.width()*this.options.dividerLocation));
+		this.availableContainer.width(Math.floor(this.element.width()*(1-this.options.dividerLocation)));
+
+		// fix list height to match <option> depending on their individual header's heights
+		this.selectedList.height(Math.max(this.element.height()-this.selectedActions.height(),1));
+		this.availableList.height(Math.max(this.element.height()-this.availableActions.height(),1));
+
+	},
+
 	_populateLists: function(options) {
 		this.selectedList.children('.ui-element').remove();
 		this.availableList.children('.ui-element').remove();