Still nothing. It doesn't create my EventHandler, because when I debug with the break point on the:
myThumb_btn.Click += new System.Web.UI.ImageClickEventHandler(myThumb_Click );
it appears on the line but when is the time to go on the myThumb_Click function it goes out from the program. I try to make like they do on the link you gave me but the problem is that it creates only one thumb every time and still no click.
Thank you.

As is often the case the error is in how you are calling the code above, not in the code above, so without seeing more of your page it is impossible to answer the question.

Wherever the bit of code that calls AddThumb() is, you need to move that code to Page_Init().

/- Sam Judson : Wrox Technical Editor -/

Not that not just the ImageButton, but Conrol.Add will also need to occur on Page_Load.