find html control in in server side asp .net c#

Question

i have an image with following id

<img alt="" id="imgdiv<%# Eval("nopkj") %>"width="9px" border="0" src="image/plus.gif" /></a>

how do i find the id in server side webform in FindControl code

Image img = (Image)row.FindControl("?");

TQ for the help..