function createXMLHttpRequest() 
{       
	var xmlHttp = false;
	
	if(window.ActiveXObject) 
	{               
		xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");        
	}       
	else if(window.XMLHttpRequest) 
	{               
		xmlHttp = new XMLHttpRequest();        
	}
	else
	{               
		alert("Please upgrade your browser!  Your browser does not support AJAX!");       
	}
	
	return xmlHttp;
}



function cargaciudades(provincia, id_re_script, caso)
{
	var oRequest  = createXMLHttpRequest();
	
	var sURL  = "http://www.casas.es/cargaciudades.php?prov_id="+ provincia +"&caso_id="+caso;

	oRequest.open("GET",sURL,false);
	oRequest.setRequestHeader("User-Agent",navigator.userAgent);
	oRequest.send(null);

	if (oRequest.status==200)
	{
		document.getElementById(id_re_script).innerHTML = oRequest.responseText;
	}
	else alert("Error executing XMLHttpRequest call!");
}