// JavaScript Document
function obtenerXHR(){
var peticion=false;
if(window.XMLHttpRequest){
peticion=new XMLHttpRequest();
return peticion;
}else if(ActiveXObject){
matrizVersiones=["MSXML2.XMLHttp.5.0","MSXML2.XMLHttp.4.0","MSXML2.XMLHttp.3.0","MSXML2.XMLHttp","Microsoft.XMLHttp"];
for (i in matrizVersiones){
if(peticion==false){
peticion= new ActiveXObject(matrizVersiones[i]);
return peticion;
}

}	
}
}