  The hadronic invariant mass distribution for the process of electron-positron
annihilation into a pair of charged pions accompanied by a photon radiated from
the initial state has been studied for the region of DA$\Phi$NE energies. The
Born cross-section and the electromagnetic radiative corrections to it are
calculated for realistic conditions of the KLOE detector. The dependence on the
physical parameters which define the event selection is obtained.
