JS 屏蔽键盘与鼠标事件

<script type='text/javascript'>
var isCtrl = false;
document.onkeyup=function(e)
{
if(e.which == 17)
isCtrl=false;
}
document.onkeydown=function(e)
{
if(e.which == 17)//键盘的Ctrl键
isCtrl=true;

//67 键盘的C
if((e.which == 85) || (e.which == 67) && isCtrl == true)
{
// alert(‘Keyboard shortcuts are cool!’);
return false;
}
}
var isNS = (navigator.appName == "Netscape") ? 1 : 0;
if(navigator.appName == "Netscape") document.captureEvents(Event.MOUSEDOWN||Event.MOUSEUP);
function mischandler(){
return false;
}
function mousehandler(e){//屏蔽鼠标右键
var myevent = (isNS) ? e : event;
var eventbutton = (isNS) ? myevent.which : myevent.button;
if((eventbutton==2)||(eventbutton==3)) return false;
}
document.oncontextmenu = mischandler;
document.onmousedown = mousehandler;
document.onmouseup = mousehandler;
</script>