让Firefox也兼容Javascript脚本

function getEvent(){ //获取浏览器事件，同时兼容ie和ff的写法 
if(document.all) return window.event; 
func=getEvent.caller; 
while(func!=null){ 
var arg0=func.arguments[0]; 
if(arg0){ 
if((arg0.constructor==Event 　　 arg0.constructor ==MouseEvent) 
　　 (typeof(arg0)=="object" && arg0.preventDefault && arg0.stopPropagation)){ 
return arg0; 
} 
} 
func=func.caller; 
} 
return null; 
}

event.returnValue=false;// for IE 

evt.preventDefault();//for firefox

var source=event.srcElement //IE 

var source=event.target //firefox

function addEvent(oElement,sEvent,func){ 
if (oElement.attachEvent){ 
oElement.attachEvent(sEvent,func); 
} 
else{ 
sEvent=sEvent.substring(2,sEvent.length); 
oElement.addEventListener(sEvent,func,false); 
} 
}

//注册firefox innerText 
HTMLElement.prototype.__defineGetter__("innerText", 
function(){ 
var anyString = ""; 
var childS = this.childNodes; 
for(var i=0; i if(childS[i].nodeType==1) 
anyString += childS[i].tagName=="BR" ? '\n' : childS[i].innerText; 
else if(childS[i].nodeType==3) 
anyString += childS[i].nodeValue; 
} 
return anyString; 
} 
); 
HTMLElement.prototype.__defineSetter__("innerText", 
function(sText){ 
this.textContent=sText; 
} 
);