image scale

Hello list,

In my document I have a lot of screenshot form different size. But  
the text zone is 13 cm wide. So with :

<imagedata fileref="path/to/image.tiff" width="13cm" scalefit="1"/>

All my screenshot will be inside the text zone (if I correctly  
interested).

But with my pictures it's long to put on all width="13cm"  
scalefit="1". Is it possible to put this as default values for all  
imagedata ? May be in my custom stylesheet but I don't now how.

Thanks in advance,
Jacques
-- 
Je sais bien qu'il faut pas conduire bourré, mais on va quand même  
pas rentrer a pied. Faut pas déconner.