  It is demonstrated that event generators LEPTO and PYTHIA can be modified to
describe some azimuthal modulations. The comparisons of results obtained with
modified LEPTO with existing data in the current fragmentation region of SIDIS
are presented for Cahn and Sivers effects as well as the predictions for the
target fragmentation region. The predictions for Sivers effect in the
Drell--Yan process obtained with modified PYTHIA are also presented. The
concept of hadronization function is discussed.
