屏蔽按键

<html>

function document.onkeydown() { //屏蔽鼠标右键、Ctrl+n、shift+F10、F5刷新、退格键

//alert("ASCII代码是："+event.keyCode);

if ((window.event.altKey)&&

((window.event.keyCode==37)|| //屏蔽 Alt+ 方向键 ←

(window.event.keyCode==39))){ //屏蔽 Alt+ 方向键 →

alert("不准你使用ALT+方向键前进或后退网页！");

event.returnValue=false;

}

if ((event.keyCode==8) || //屏蔽退格删除键

(event.keyCode==116)|| //屏蔽 F5 刷新键

(event.keyCode==112)|| //屏蔽 F1 刷新键

(event.ctrlKey && event.keyCode==82)){ //Ctrl + R

event.keyCode=0;

event.returnValue=false;

}

if ((event.ctrlKey)&&(event.keyCode==78)) //屏蔽 Ctrl+n

event.returnValue=false;

if ((event.shiftKey)&&(event.keyCode==121)) //屏蔽 shift+F10

event.returnValue=false;

if (window.event.srcElement.tagName == "A" && window.event.shiftKey)

window.event.returnValue = false; //屏蔽 shift 加鼠标左键新开一网页

if ((window.event.altKey)&&(window.event.keyCode==115)){ //屏蔽Alt+F4

window.showModelessDialog("about:blank","","dialogWidth:1px;dialogheight:1px");

return false;}

}

function Showhelp(){

alert("Wrong!");

return false;

}

</script>

<body>

body text

</body>

</html>