ScriptManager.RegisterStartupScript code not working – why?

Off the top of my head:

• Use GetType() instead of typeof(Page) in order to bind the script to your actual page class instead of the base class,
• Pass a key constant instead of Page.UniqueID, which is not that meaningful since it’s supposed to be used by named controls,
• End your Javascript statement with a semicolon,
• Register the script during the PreRender phase:

---

protected void Page_PreRender(object sender, EventArgs e)
{
    ScriptManager.RegisterStartupScript(this, GetType(), "YourUniqueScriptKey", 
        "alert('This pops up');", true);
}