function disableCtrlModifer(evt) { var disabled = {a:0, c:0, x:0, v:0}; var ctrlMod = (window.event)? window.event.ctrlKey : evt.ctrlKey; var key = (window.event)? window.event.keyCode : evt.which; key = String.fromCharCode(key).toLowerCase(); return (ctrlMod && (key in disabled))? false : true; }