var ultima_cargada = 'prueba';

function generar_ajax() {
	var objeto;
	if (window.XMLHttpRequest) {
		objeto = new XMLHttpRequest();
	} else {
		if (window.ActiveXObject) {
			try {
				objeto = new ActiveXObject('Msxml2.XMLHTTP');
			} catch (e) {
				try{
					objeto = new ActiveXObject('Microsoft.XMLHTTP')
				} catch (e){
					objeto = false;
				}
			}
		} else {
			objeto = false;
		}
	}
	return objeto;
}

function envio(cargar) {
	var transmision = generar_ajax();
	if (!transmision) {
		alert('Su navegador no acepta ajax');
	} else {
		transmision.onreadystatechange = function () {
			recepcion(transmision, cargar);
		}
		transmision.open('POST', '../inc/cargas.inc.php', true);
		transmision.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
		transmision.send('&cargar=' + cargar);
	}
}

function recepcion(transmision, cargar) {
	if ((transmision.readyState == 4) && (transmision.status == 200 || window.location.href.indexOf('http') == -1)) {
		document.getElementById('contenedor_pagina').innerHTML = transmision.responseText;
		if (cargar = 'contacto') {
			 initialize()
		} else {
			if (ultima_cargada = 'contacto') {
				GUnload()
			}
		}
		ultima_cargada = cargar;
	}
}