后台弹出对话框

Page.ClientScript.RegisterStartupScript(this.GetType(), "", "window.alert('直接写这句话就可了');", true);

Response.Write("<script language=javascript>alert('删除成功！')</script>");

ajax:ScriptManager.RegisterStartupScript(this, GetType(), "128", "alert('删除加油卡成功！');", true);