Make the attachment to a WI mandatory

[Fabrice Turboult]

Dear all,
 
For a task which needs to be confirmed at the end of its processing, our wish is to make
the attachment mandatory. But in our version (R/3 4.5B), this is an option among the following ones:
   complete processing of step
   create attachment
   display attachment
   cancel
therefore, it is possible to complete the step without creating any attachment.
 
Do you have any idea to get this attachment mandatory ?
Thank you in advance
Regards.
 
Fabrice Turboult