Plane-parallel magnetic fields in a thin galactic gaseous disk in random motion

A Fokker-Planch-type equation for describing magnetic fluxes in the gaseous component in random rising and falling motion in the galactic disk is solved. If weak fields exist in the halo and if they can diffuse into the disk across its interface, the magnetic fields may be maintained stronger in the disk without recourse to a dynamo action. We stress that the dynamo is rather necessary in the halo of a larger extent. (author)