protected void btnLogin_Click(object sender, EventArgs e) { string username = txtUsername.Text.Trim(); string password = txtPassword.Text.Trim(); StaffDTO staff = null; StaffDAO dao = new StaffDAO(); bool result = dao.CheckLogin(username, password, ref staff); if (result) { Session["STAFF_USER"] = staff; Response.Redirect("StaffWorkspace.aspx"); } else { this.invalidLogin.CssClass = "error_message_show"; this.txtPassword.Text = ""; } }