attaching event handler to button created at buttonclick

Hello All,
I am trying to do something very straight-forward, except that its behaving very fishy.
 
First off, i am reading few records off the database and displaying then on the page, as soon as it loads. Each record goes in 2 panels, which i am creating at runtime, and extending using ajax collapsable panel extender. something like this:
while (reader.Read())
        {
            Panel p1 = new Panel();
            Panel p2 = new Panel();

            string P2Content = "";

            p1.ID = "Header" + counter.ToString();
            p1.CssClass = "PanelHeader";
  ...