Where should I place the ScriptManager.RegisterStartupScript to call my javascript

Question

I am trying to use ScriptManager.RegisterStartupScript but I am not sure where to place it. For example: on a page load, or inside a DeleteButtonClick even handler method. On my page there's a delete asp.button. And I want to call my JavaScript function every time when a user clicks on the delete button. Thanks

Answer 1

Register the script during the PreRender phase:

protected void Page_PreRender(object sender, EventArgs e)
{
    ScriptManager.RegisterStartupScript(this, GetType(), "Key", 
    "alert('call in pre-render');", true);
}