it only needs to work in Internet Explorer.
it has solve your problem,
when you will press ctrl+t(or any other combination) it will return you perticularkeyCode using which you can identify the key combination.
in IE you can capture keyCode using window.event.keyCode
use document.onkeypress to capture keypress event on whole document.
see this also.
hope this will solve your problem.
following example may help you:
<html>
<head>
<script type="text/javascript">
document.onkeypress=function()
{
alert(window.event.keyCode);
}
</script>
</head>
</body>
this example will work in IE 6
</body>
</html>