How to generate debuginfo rpm package on OpenSUSE 11.2

I am using OpenSUSE 11.2.
When I use “# rpmbuild -ba xxxx.spec” to create rpm packages of xxxx, the operation is successful but no debuginfo package is generated.
Anybody can tell me why?
Is there any solution or suggestion to this problem?

That programm you must have. Right??

Easy RPM Builder

I mean how to generate debuginfo rpm package by rpmbuild.
Should I use any options, modify any configuration items or specify anything in the spec file?