asp.net后台显示确认框

asp.net后台显示确认框:

System.Windows.Forms.DialogResult key = MessageBox.Show("该公文已通过审核，确定删除吗？", "警告", MessageBoxButtons.YesNo, System.Windows.Forms.MessageBoxIcon.Warning);
                    if (key == DialogResult.Yes)
                    {
                        bool result = bll.Delete(Convert.ToInt32(i));
                        string str0gwsh = "delete gw_sh where gwid='" + i + "'";
                        string str0gwAip = "delete AIP_SignData where actid='" + i + "'";
                        gxjt.DBUtility.DbHelperSQL.ExecuteSql(str0gwsh);
                        gxjt.DBUtility.DbHelperSQL.ExecuteSql(str0gwAip);
                    }
                    else
                    {
                        return;
                    }