function ajaxFunction() {
	var xmlHttp;
	try {
		// Firefox, Opera 8.0+, Safari
		xmlHttp=new XMLHttpRequest();
		return xmlHttp;
	} catch (e) {
		// Internet Explorer
		try {
			xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
			return xmlHttp;
		} catch (e) {
			try {
				xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
				return xmlHttp;
			} catch (e) {
				alert("Tu navegador no soporta AJAX!");
				return false;
			}
		}
	}
}
function Mostrar(_pagina,capa) {
	var ajax;
	ajax = ajaxFunction();
	ajax.open("GET", _pagina, true);
	ajax.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset=ISO-8859-1'); 
	ajax.onreadystatechange = function(){
		if (ajax.readyState==1){
			document.getElementById(capa).innerHTML = "<center><span class='loading'>Please Wait</span></center>";
		}
		if (ajax.readyState == 4){
			if (ajax.status==200){
				document.getElementById(capa).innerHTML = ajax.responseText;
			}else{
				alert(ajax.status)
			}
		}
	}
	ajax.send(null);
}
/*function Campos(opcion) {
	if(opcion==2){
		document.getElementById('titulo1').innerHTML = "City:";
		document.getElementById('titulo2').innerHTML = "Airport:";
	}
}*/