protected void Page_Load(object sender, EventArgs e) { if (!String.IsNullOrEmpty(Request["TextBoxTaiKhoan"])) { string TextBoxTaiKhoan = Request["TextBoxTaiKhoan"].Trim(); if (!String.IsNullOrEmpty(Request["UserName"])) { if (Request["UserName"] == TextBoxTaiKhoan) { Response.Write("-1"); } else { if (QuanTriVien.isUsernameExist(TextBoxTaiKhoan)) { Response.Write("1"); } else { Response.Write("-1"); } } } else { if (QuanTriVien.isUsernameExist(TextBoxTaiKhoan)) { Response.Write("1"); } else { Response.Write("-1"); } } } }