function obtener()
{
	con=false;
	if(window.XMLHttpRequest)
	{
		con=new XMLHttpRequest();
	}
	else
	{
		if(ActiveXObject)
		{
			var aVersiones=["MSXML2.XMLHttp.5.0","MSXML2.XMLHttp.4.0","MSXML2.XMLHttp.3.0","MSXML2.XMLHttp","Microsoft.XMLHttp"];
			for(var i=0; i<=aVersiones.length;i++)
			{
				try
				{
					con= new ActiveXObject(aVersiones[i]);
					return con;
				}
				catch (e){}
			}
		}
	}
	return con;
}
function aparecer(div)
{
	var d=document.getElementById(div);
	d.style.position='fixed';
	d.style.width='500px';
	d.style.height='400px';
	d.style.marginLeft='50%';
	d.style.marginTop='50%';
	d.style.left='-250px;';
	d.style.top='-200px';
	var datos="";
	aj.open("POST","../php/menu.php",true);
	aj.onreadystatechange=function(){
		if (aj.readyState == 4) {
			if (aj.status == 200) {
				d.innerHTML=aj.responseText;
				d.style.visibility='visible';
			}
		}
	}
	aj.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
	aj.send(datos);
}