public JsonResult ValidateUser(string Username)
 {
     try
     {
         if (Request.IsAjaxRequest())
         {
             var result = _RegistrationBL.ValidateUser(Username);
             return(Json(result, JsonRequestBehavior.AllowGet));
         }
         else
         {
             return(Json("Failed", JsonRequestBehavior.AllowGet));
         }
     }
     catch (Exception)
     {
         throw;
     }
 }