Can I Substitute Hard Drive from a Latitude to a HP Omnibook?

I have been given an HP Omnibook 6100 laptop without a hard drive. Can I use a hard drive from either:
(A) A Dell Latitude C840 (which is a ?40GB (5, 400RPM) 9.5MM IDE HARD DRIVE?)
or
(B) a Dell Latitude C600 (which is a ?C 10GB IDE HARD DRIVE?)?

Thanks