js 小demo

/** * 屏蔽F5 */function onkeydown(){if (event.keyCode==116){event.keyCode = 0;event.cancelBubble = true;return false;}}document.onkeydown = this.onkeydown;/** * 屏蔽鼠标右键  */function norightclick() {window.event.returnValue=false; }document.oncontextmenu = this.norightclick;

if(self.location != top.location) {  top.location = self.location ;}function isIE6(){String.prototype.inc=function(k1,k2){return k2==null?this.indexOf(k1)>-1?true:false:(k2+this+k2).indexOf(k2+k1+k2)>-1?true:false}var agent=navigator.userAgentvar isIE,isIE4,isIE5,isIE6,isOpr,isMozisOpr=agent.inc("Opera")isIE=agent.inc("IE")&&!isOprisIE4=agent.inc("IE 4")isIE5=agent.inc("IE 5")||agent.inc("IE 4")isIE6=isIE&&!isIE5isMoz=agent.inc("Mozilla")&&!isOpr&&!isIEif(!isIE6){   alert("建议您使用IE6.0、IE7.0或IE8.0的浏览器进行报名！");}}