<Script language="javascript">
function checkKeyCode(evt)
{
var evt = (evt) ? evt : ((event) ? event : null);
var node = (evt.target) ? evt.target : ((evt.srcElement) ? evt.srcElement : null);
if(event.keyCode==116)
{
evt.keyCode=0;
return false
}
}
document.onkeydown=checkKeyCode;
</script>
I tried this it is working fine in IE but it doesn't work in Firefox.................please help me.