Custom Widgets

Hi 

I'm having a problem with using a custom widget. 

I have added the line 
     setattr(self, macro_view, ‘’) 
in the image class in Archetypes/Widget.py and created a widget macro_image in my plone_skins/custom folder.
However the Widget is not called, I'm pretty sure I did this this way before but I could be remembering wrongly. 

Can anyone help please, I may have gone veering completely of track

Charlotte