Application_Error Ajax

Application_Error.cs

var header = context.Request.Headers["X-Requested-With"];
            if (!string.IsNullOrEmpty(header) && header.ToLower().IndexOf("xmlhttp") >= 0)
            {
                Server.ClearError();
                Response.StatusCode = 400;
                Response.Clear();
                Response.Write(exception.Message);
                Response.End();
                return;
            }