Setting focus to a web control

Can anyone give me some VB to set focus to a control using the "FindControl" method. MyTextbox.focus() is not good enough
because, for instance, I have a textbox called "Username" in the "CreateNewUserWizard" control which is within a Contentplaceholder on a child page so typing in "Username.focus()" does not work on the Page_Load event because Username simply does not have a Focus property.
 
help help
 
many thanks
 
...