Similar to the Page.RegisterClientScriptBlock(string, string) method, the Page.RegisterStartupScript(string, string) method emits the script just before the closing tag of the System.Web.UI.Page object's <form runat= server> element. Be sure to include opening and closing <script> elements around the script block string specified in the script parameter.

Because this method uses a key to identify the script block, the script block does not have to be emitted to the output stream each time it is requested by a different server control instance

Any script blocks with the same key parameter values are considered duplicates.

The Page.RegisterStartupScript(string, string) method has been deprecated. Use the erload:System.Web.UI.ClientScriptManager.RegisterStartupScript method in the System.Web.UI.ClientScriptManager class instead.