Remember which tab was active after refresh

I assume that you are using jQuery UI tabs ,

here is an example of using tabs + cookies to save the last clicked tab

http://jqueryui.com/demos/tabs/#cookie

demo : open this link http://jqueryui.com/demos/tabs/cookie.html

the close it and re open it and you will see the same clicked tab

update: after 3 years of this answer jquery ui has deprecated the cookie option : http://jqueryui.com/upgrade-guide/1.9/#deprecated-cookie-option.

but you can still append take a look here if this fits your needs or not https://stackoverflow.com/a/14313315/109217

Like others I was struggling with my ui-tabs cookie history in jQueryUI 1.10. Thanks to Harry's solution and some other online documentation I refer to in the code below I now have a working non-cookie solution! I was able to test in Firefox 18.0.1 and IE 9.0.12. According to my resources, Chrome, Firefox, Safari and IE8 & above support Session Storage.

  $(function() {
    //  jQueryUI 1.10 and HTML5 ready
    //      http://jqueryui.com/upgrade-guide/1.10/#removed-cookie-option 
    //  Documentation
    //      http://api.jqueryui.com/tabs/#option-active
    //      http://api.jqueryui.com/tabs/#event-activate
    //      http://balaarjunan.wordpress.com/2010/11/10/html5-session-storage-key-things-to-consider/
    //
    //  Define friendly index name
    var index = 'key';
    //  Define friendly data store name
    var dataStore = window.sessionStorage;
    //  Start magic!
    try {
        // getter: Fetch previous value
        var oldIndex = dataStore.getItem(index);
    } catch(e) {
        // getter: Always default to first tab in error state
        var oldIndex = 0;
    }
    $('#tabs').tabs({
        // The zero-based index of the panel that is active (open)
        active : oldIndex,
        // Triggered after a tab has been activated
        activate : function( event, ui ){
            //  Get future value
            var newIndex = ui.newTab.parent().children().index(ui.newTab);
            //  Set future value
            dataStore.setItem( index, newIndex ) 
        }
    }); 
    });