  We make some remarks on possible definition of open string path integral in
the presence of additional boundary couplings corresponding to the presence of
masses at the ends of the string. These couplings are not conformally invariant
implying that as in a non-critical string case one is to integrate over the 1d
metric or reparametrizations of the boundary. We compute the partition function
on the disc in the presence of an additional constant gauge field background
and comment on the structure of the corresponding scattering amplitudes.
