I can add own context menu on right click.. But if first opens defult context menu

How to disable defult context menu and show directly the custom context menu on grid right click...

For IE I do...

grid.getCellTemplate().setEvent("oncontextmenu", function () {
event.returnValue = false;
show_context_menu();
});

I also had to this:

if (window.event)
window.event.cancelBubble = true;
else
evt.stopPropagation();