Obtain Event object and keyCode_javascript techniques under Firefox

Copy code The code is as follows:

var isie = (document.all) ? true:false;
var key;
var ev;
if(isie){
key = window.event.keyCode;
ev = window.event;
}else{
key = e .which;
ev = e;
}

At this time, you can alert(key) to see,
But if you want to use
ev.returnValue = true; // IE
ev.preventDefault(); // Mozilla Firefox