[jQuery] variable scope

[jQuery] variable scope


Hello everyone,
I'm new to jQuery and need some help with a trivial question. I'm
trying to program a menu bar and I'm having problems with variable
scope. Below is a snippet of my code:
//
******************************************************************************************************
<script type="text/javascript">
    $(document).ready(function()
    {
     var menubar = new MenuBar();
    });
</script>
<script type="text/javascript">
    function MenuBar()
    {
        this.currentIndex = 0;
        $('.menu_button').click(this.onClick);
    };
    MenuBar.prototype.onClick = function(evt)
    {
        this.currentIndex = 1; //<--Unable to access class variable!!
        this.Select(this.currentIndex); //<--Unable to access class
funtion!!
    };
    MenuBar.prototype.Select = function(index)
    {
        //code goes here
    };
</script>
//
******************************************************************************************************
Once the onClick event is received the scope move from the class to
the actual item itself. How do I access class variables amd functions
after receiving an event??
Any help is greatly appreciated.
-Ted