[web2py] css handling at custom form

[pk]

hi together,
i need very important help:

i have this code example:

 {{=foto_edit.custom.begin}}
   Image file: <div>{{=XML("%s%s" %
(str(foto_edit.custom.widget.image).split("[")[0], '</div>'))}}</div>
   Click here to upload: {{=foto_edit.custom.submit}}
  {{=foto_edit.custom.end}}

how can i handle the css for the buttons the labels and the filename?

thanks peter