Problem in getting index for currently selected tab using option 'selected'

Problem in getting index for currently selected tab using option 'selected'

I am using the Tabs widget and already have it working in a <div> named 'navbar'.
Now I need to fetch the index of currently selected tab in one of the event handler functions.

According to the documentation for Tabs :

Get or set the selected option, after init.
  1. //getter
    var selected = $( ".selector" ).tabs( "option", "selected" );

But instead of getting a number (index) in var 'selected', i am getting an object representing the current tab.
How do i obtain the index?

My code is as follows:
  1. var selected = $( '#navbar' ).tabs( "option", "selected" );
  2. if(selected==0){
  3.       //do some thing based on selected tab index
  4.       alert("in tab 0");
  5.       }
  6. alert("loaded "+selected);