function nuevoAjax(){
var xmlhttp=false;
	try {
		xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
	} catch (e) 
	{
		try {
			xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
		} catch (E) {
			xmlhttp = false;
		}
	}
	
	if (!xmlhttp && typeof XMLHttpRequest!='undefined') {
		xmlhttp = new XMLHttpRequest();
	}
	
	return xmlhttp;
}


function ajax(pag){
	
	var contenedor = document.getElementById('ajax_load');
		ajx=nuevoAjax();
		ajx.open("GET", pag,true);
		ajx.onreadystatechange=function() {
			if (ajx.readyState==4) {
				contenedor.innerHTML = ajx.responseText
			}
		}
		ajx.send(null)
}