Called when a panel content is set or changed. You can add event listener during the object creation: $('#layout').w2layout({ name : 'layout', panels : [ { type: 'top', size: 40 }, { type: 'preview', size: 200 } ], onContent: function(event) { console.log('content changed for '+ event.panel); } }); or after the object has been created: w2ui.layout.on('content', function(event) { console.log('content changed for '+ event.panel); }); You can add a listener to a panel, see .panels property. The event handler is called before the default action of the event is triggered. You can cancel the default action by calling event.preventDefault(). To perform an action after the event is fully processed, define event.onComplete function. See events page in utilities for more details.