<%@ page language="C#" %> <script runat="server"> void Page_Load(object sender, System.EventArgs e){ this.ClientScript.RegisterStartupScript(this.GetType(), "startupalert", "alert('Hello world!');", true); } </script> <html> <head runat="server"> <title>Untitled Page</title> </head> <body> <form runat="server"> </form> </body> </html>