It all depends on the severify level of your error. If you raise your between between 11 and 16 then we will stop generation. Any errors below are just information, as such we output the error but continue.
You can find out more information on MSDN - http://msdn.microsoft.com/en-us/library/aa937483(SQL.80
For example, this will stop generation:
Where as, this will just output a message:
RAISERROR('This is just some information',1,1)
I hope this helps.