No me carga el php

[bichomen]

pego el codigo ajax:

Código:

var isIE = false;
var req;

function cargaXML(url) 
{
	if(url=='')
	{
        alert("No se esta pasando niguna direccion");
		return;
    }
    
	if (window.XMLHttpRequest) 
	{
        req = new XMLHttpRequest();
        req.onreadystatechange = processReqChange;
        req.open("GET", url, true);
        req.send(null);
    } 
	else if (window.ActiveXObject) 
	{
        isIE = true;
        req = new ActiveXObject("Microsoft.XMLHTTP");
        if(req) 
		{
            req.onreadystatechange = processReqChange;
            req.open("GET", url, true);
            req.send();
        }
    }
}

function processReqChange()
{
	var detalles = document.getElementById("detalles");
    
	if(req.readyState == 4)
	{
        alert("1 " + req.responseText);
		detalles.innerHTML = req.responseText;
    } 
	else 
	{
		 alert("2 " + detalles.innerHTML);
		detalles.innerHTML = "Cargando...";
    }
}

bichomen