If your blower suddenly stopped, it's most likely one of the following:
- push button control unit
- blower motor regulator
Unfortunately both parts are quite expensive. Do a search on "blower motor" and you'll learn how to test the system to pinpoint the problem.
If you're lucky, it could be the fuse as haasman indicated.
'01 E430, Sport 72,000 mi
'98 C280, 126,500 mi