problems merging from branch to mainline

[Daniels, Dave F]

Hi,

I'm having some trouble merging from a branch to the mainline. The latest
branch version is 1.1.2.9, while the latest mainline version is 1.2. I'm
running this command from a checked-out copy of the mainline:

cvs update -j1.1.2.9 foo.jsp

What I expected to happen was file 'foo.jsp' would be updated from the
changes in 1.1.2.9, which I would turn around and commit. Instead, I get the
message:

cvs server: file foo.jsp exists, but has been added in revision 1.1.2.9

How to I merge my changes from my branch to the mainline in this case?

Thanks,
Dave