No dude.....
you have to clear
SCJP before going for SCWCD
SCJP is a fundamental certification,after clearing this you can got any of the following certifications
SCWCDSCBCDSCJD etc
You can use the same voucher for any of the Certification exams.
Anyway Best of luck for your SCJP preperations.

[ December 08, 2008: Message edited by: harilal ithikkat ]