Conversion from MSSQL 2000 to MSSQL 2005

We have a membership web site that is heavily database driven using MSSQL 2000. We are looking at converting to MSSQL 2005. What is the level of pain in doing this? Will all database calls have to be rewritten, or does Microsoft provide any kind of automatic conversion routine. Thanks in advance.U need to upgrade the database to the next version.

u dont have to rewrite the procs/functions.

Under the watch ful eye of an able SQL-DBA u can do it with out much hassles.