protected void btnXoa_Click(object sender, EventArgs e)
        {
            tbll.XoaTin(txtMaTin.Text);
            Page_Load(sender, e);
            Response.Write("<script language=''javascript>alert('" + " Xóa thành công! " + "')</script>");

            txtMaTin.Text         = "";
            txtTieuDe.Text        = "";
            txtTomTat.Text        = "";
            txtHinhAnh.Text       = "";
            CKEditorControl1.Text = "";
            txtNgayDang.Text      = "";
            txtLuotXem.Text       = "";
            txtTrangThai.Text     = "";
        }