How to get the instance of the object (Tabbar) in case if it

I Initialized TabBar object from HTML structure, Now I want to get the active tab. How can I do it?

You can use id of the htmlx container like instance of the tabbar:
<div id=“a_tabbar” class=“dhtmlxTabBar” imgpath=“codebase/imgs/” style=“width:390; height:390;” skinColors="#FCFBFC,#F4F3EE" >

<input type=“button” value=“next” onclick=“alert(a_tabbar.getActiveTab())” />