  If H is a quasi-Hopf algebra and B is a right H-comodule algebra such that
there exists v:H\to B a morphism of right H-comodule algebras, we prove that
there exists a left H-module algebra A such that B\simeq A# H. The main
difference comparing to the Hopf case is that, from the multiplication of B,
which is associative, we have to obtain the multiplication of A, which in
general is not; for this we use a canonical projection E arising from the fact
that B becomes a quasi-Hopf H-bimodule.
