how to find recursively controls in C# asp.net

private Control FindControlRecursive ( Control root, string id )
{
try
{
if (root.ID == id)
{
return root;
} //eof if

foreach (Control c in root.Controls)
{
Control t = FindControlRecursive ( c, id );
if (t != null)
{
return t;
} //eof if
} //eof foreach
} //eof try
catch (Exception e)
{
Debugger.WriteIf ( "The following Exception occured : \n" + e.Message );
this.Master.Error_label.ForeColor = System.Drawing.Color.Red;
this.Master.Error_label.Text = e.Message;
return success;
} //eof catch

return null;
} //eof FindControlRecursive