Dynamically removing tab entries after dynamically adding them

Dynamically removing tab entries after dynamically adding them

I'm creating tabs dynamically with:

    <div id="tt" class="easyui-tabs" >
    </div>

        function addTab(title, url){
                var content = '<iframe scrolling="auto" frameborder="0"  src="'+url+'" style="width:100%;height:100%;"></iframe>';
                $('#tt').tabs('add',{
                    title:title,
                    content:content,
                    closable:true
                });
        }

I need to remove them dynamically.  The suggestion from the man page is: 
$( "#tt" ).tabs( "destroy" );

This produces the error:
Uncaught TypeError: undefined is not a function jquery.easyui.min.js:4817

How do I remove dynamically created tabs?