Problema en firefox

[conetsol]

Hola A todos estoy con un problema con firefox, tengo una aplicación que corre en IE perfectamente pero cuando trabajo en firefox no funciona,

Adjunto el código para que me puedan hechar una manito:


Función AJAX:

Código HTML:

/***************************************************************** /
	AJAX - Asynchrynous Javascript And XML
	--------------------------------------
	
	The code in this section serves to clarify the way by which
	you can use the AJAX metod to streamline content loading
	in your site to more closely resemble desktop applications.
	
	Due to the minimized amount of data travelling between server
	and client, this process will serve to speed up the reactive-
	ness of your site considerably while at the same time allowing
	your client to have full view of the framework of your website.
/******************************************************************/
//Define the XMLHttpRequest function to return an instance of Microsofts XMLHTTP object
window.XMLHttpRequest = function() {
    return new ActiveXObject((navigator.userAgent.toLowerCase().indexOf('msie 5') != -1) ? 'Microsoft.XMLHTTP' : 'Msxml2.XMLHTTP');
};

window.statusFlash = function(msg,seconds){
	if(window._t_statusFlash){
		clearTimeout(window._t_statusFlash);
	}else{
		window.oldStatus=window.status;
	}
	window._t_statusFlash = setTimeout('window.status=window.oldStatus',seconds*1000);
	window.status=msg;
}

//###### QUICKCREATE MESSAGEBOX
	document._createMessageBox=function(heading,content){
		var ret='<table width="100%" height="100% cellspacing="0" cellpadding="0" style="border: 1px solid #333333">';
		ret=ret+'<tr><td height="1" style="font-family: Arial; font-size: 12px; font-weight: bold; background-color: #6A6A6A; color:#F4F4F4; text-align: center;">';
		ret=ret+heading;
		ret=ret+'</td></tr>';
		ret=ret+'<tr><td style="font-family: Arial; font-size: 11px; font-weight: normal; background-color:#F4F4F4; color: #333333; text-align: center; vertical-align: middle;">';
		ret=ret+content;
		ret=ret+'</td></tr>';
		ret=ret+'</table>';
		return ret;
	}

	divTags=document.all.tags('DIV');
	for(curTag=0;curTag<divTags.length;curTag++){
		cDiv=divTags[curTag];
		cDiv.loadStatus=false;
		cDiv.load=function(url){
			if(!this.isLoading){
				window.statusFlash('Cargando Contenido...',1);
				if(this.loadmessage){
					this.innerHTML=document._createMessageBox('Procesando...',this.loadmessage);
				}
				var lPause=0;
				if(this.loadpause)lPause=this.loadpause*1000;
				this._LREQ=new XMLHttpRequest();
				eval('this._LREQ.onreadystatechange=function(){document.getElementById("'+this.id+'")._load();}');
				this._LREQ.open('GET',url);
				this._LREQ.send(null);
				this.isLoading=true;
				var ltimeout=3;
				if(this.load_timeout)ltimeout=this.load_timeout;
				setTimeout('document.getElementById("'+this.id+'").isLoading=false',ltimeout*100);
				
			}
		}
				
		cDiv._load=function(){
				if(this._LREQ.readyState==4){
					if(this._LREQ.status==200){
						this.innerHTML=this._LREQ.responseText;
						this.isLoading=false;
					}else{
						this.innerHTML='Error en la carga de datos XHTTP: '+this._LREQ.status;
						this.isLoading=false;
					}
				}
		}
	}

Función que hace el llamado al AJAX dentro de mi página:

Código HTML:

<script>


function funcambiob(){
	a = "consopc.php";
	lod = (a);
	contentareab.load(lod);

}


//-->
</script>