ds_basel

I am working in MOSS 2007 and SPD 2007. I have created a workflow in SPD that involves a task list item. This task list item has a mandatory choice field. Unfortunately MOSS does not check if the field has been filled in by the user. The user can click "Complete Task" and the task will be completed although the mandatory field is still empty. The web form shows an asterix * behind the mandatory field and it looks all as if it should work. However it doesn't.

Does anyone have an idea how to get arround this Thanks.