JavaScript Var 'Undefined' in Firefox; IE and Opera Work fine

I have some JavaScript that works fine in IE and Opera, but not Firefox.

The issue seems to be that Firefox is seeing the variable as undefined.

Do I have to declare that variable even though it should be inherited?

Your problem is that you're using document.all, and .innerText, neither of which are standard.

You should be using document.getElementById() to grab items, and .innerHTML to read their contents, if they're not form inputs.

If they are inputs, use .value instead of .innerText

Firfox支持：document.getElementById("c0").textContent
IE支持： document.getElementById("c0").innerText

<mce:script   language="javascript"   ><!--
function   isIE(){
//alert("")
//alert(window.navigator.userAgent)
//alert(window.navigator.userAgent.toString().toLowerCase().indexOf("msie"))
if   (window.navigator.userAgent.toString().toLowerCase().indexOf("msie") >=1)
return   true;
else
return   false;
}
//alert(isIE())

if(!isIE()){   //firefox   innerText   define
HTMLElement.prototype.__defineGetter__(           "innerText",
function(){
var   anyString   =   "";
var   childS   =   this.childNodes;
for(var   i=0;   i <childS.length;   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;
}
);
}
alert(document.getElementById("aaaa").textContent)
alert(document.getElementById("aaaa").innerText)
// --></mce:script>