call javascript from code behind

    8     <asp:UpdatePanel ID="UpdatePanel1" runat="server"

    9         UpdateMode="Conditional" >

   10         <ContentTemplate>

   12             <asp:Button ID="Button1" runat="server" Text="Button"

   13                 onclick="Button1_Click" />

   14         </ContentTemplate>

   15     </asp:UpdatePanel>

.................

   17         protected void Button1_Click(object sender, EventArgs e)

   18         {

   21             string script = "alert('Message')";

   22             ScriptManager.RegisterClientScriptBlock(UpdatePanel1,

   23                 typeof(UpdatePanel), "jscript", script, true);

   25         }

thanks to link