function AJAXCrearObjeto(){
	var http_request = false;
	var textoError='';
	
	if (window.XMLHttpRequest) { // Mozilla, Safari,...
		try{
			http_request = new XMLHttpRequest();
			if (http_request.overrideMimeType) {
				http_request.overrideMimeType('text/xml');
			}
		} catch(e){
			textoError=e.description;
		}
		
	} else if (window.ActiveXObject) { // IE
		try {
			http_request = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			try {
				http_request = new ActiveXObject("Microsoft.XMLHTTP");
			} catch (e) {
				textoError=e.description;
			}
		}
	}

	if (!http_request) {
		alert(textoError);
		return false;
	} else {
		return http_request;
	}
}	

function cargarPagina( http_request, id_contenedor){
	document.getElementById(id_contenedor).innerHTML='';
	if	(http_request.readyState == 4 && (http_request.status==200 || window.location.href.indexOf("http")==-1)){
		document.getElementById(id_contenedor).innerHTML = http_request.responseText;
	} else{
		alert('Hubo problemas con la peticion de pagina.');
	}
}

function makeRequest(url, id_contenedor) {
//	document.getElementById(id_contenedor).innerHTML='';

	var http_request = AJAXCrearObjeto();
	try{
		http_request.onreadystatechange = function(){
						if	(http_request.readyState == 4 && (http_request.status==200 || window.location.href.indexOf("http")==-1)){
							document.getElementById(id_contenedor).innerHTML = http_request.responseText;
						} 
		}
		http_request.open('GET', url, true);
		http_request.send(null);
	} catch (e) {
		alert('Ha ocurrido un error al intentar ejecutar la peticion de pagina.');
	} 
}