Get needed behaviour onkeyup

Hello,

This is the code I use to

<script type="text/javascript">
function ControlKey(event) {
        
    switch (event.keyCode)
    {
    case 9:
        if(active_id!='') {
        Edit();
        }
        break;
    case 13:    
        break;
    }
}

  $(document).ready(function () {
     $(window).keyup(function(event) {
     ControlKey(event);
     });
});

Select allOpen in new window

Function Edit() is online editor, so it transforms table cell to select form. It works.

But the problem is that when I press tab (being inside of select) browser (Firefox) first gives focus to address , then to the next focusable element .
Only when (after few tabs) it comes back to the same select form and I press tab again I get function Edit() working.
So it looks like browser fires own event on tab and ignoring my custom.

An idea how to solve it?