Date of the first day of a week

[visual fzz]

Hi everybody

I want to know the date of the first day of a week.
Example: I choose a date : the 5th of MAY 2003.
I can have the week (between 1 and 52)
But I want the date of the first day of this week.
I can get the day (monday, tuesday...) and if I know how many days there are in the month I can move backward until the first day.
Is there a method faster and easier than this one???

Fzz