trival:
   
    // find all controls on page that start with "Tbl"

    Control[] list = ControlWalker(this, delegate(Control ctl)
    {
           return ctl.ID != null && ctl.ID.StartsWith("Tbl");
    });
   
   ......

   public delegate bool ControlWalkerMatcher (Control ctl);
   public Control[] ControlWalker(Control ctl, ControlWalkerMatcher matcher)
   {
       ArrayList list = new ArrayList();
       if (matcher(ctl)) list.Add(ctl);
       for (int i=0; i < ctl.Controls.Count; ++i)
       {
           Control[] childList = ControlWalker(ctl.Controls[i],matcher);
           if (childList.Length > 0) list.AddRange(childList);
       }
       return (Control[]) list.ToArray(typeof(Control));
   }

-- bruce (sqlwork.com)