Login C# (ASP.Net) Admin กับ User ครับ ทำไมมันไปเเต่หน้า USER ไม่ทราบว่าผิดพลาดตรงไหนครับ?

   {
            String strConnString;
            strConnString = "Server=localhost;UID=sa;PASSWORD=12345;database=mydatabase";
            objConn = new System.Data.SqlClient.SqlConnection(strConnString);
            objConn.Open();

            String strSQL;
            strSQL = " SELECT  * FROM Register WHERE UserName = '" + this.txtUsername.Text + "' AND [Password] = '" + this.txtPass.Text + "' ";
            dtAdapter = new System.Data.SqlClient.SqlDataAdapter(strSQL, objConn);
            dtAdapter.Fill(dt);

            if (dt.Rows.Count > 0)
            {
                Session["strUserID"] = dt.Rows[0]["UserID"].ToString();
                Session["strUser"] = this.txtUsername.Text;
                if (Session["Status"] == "ADMIN")
                {
                    Response.Redirect("ADMIN.aspx");
                }
                else 
                {
                     Response.Redirect("USER.aspx");
                }
 
            }
            else
            {
                this.lblStatus.Visible = true;
                this.lblStatus.Text = "กรุณาตรวจสอบ Username&Password!!";
            }

            dtAdapter = null;
            objConn.Close();
            objConn = null;
        }