The virtual bremsstrahlung process, in addition to real photon bremsstrahlung, provides an elaborate tool for studying the nucleon-nucleon interaction. The additional degree of freedom which exists in the virtual bremsstrahlung production, a longitudinal polarization of the virtual photon, allows transversal, longitudinal, and interference terms to be studied. The measurement of virtual bremsstrahlung production in proton-proton scattering was carried out at KVI using the AGOR facility. We used a 190 MeV proton beam and a liquid hydrogen target. A coincidence setup of two detector systems was employed for an exclusive measurement. The extracted interference response functions are shown and compared to the LET calculation which has a detector response folded in with Monte Carlo technique. The results presented are preliminary. The calculations are normalized to the data using one arbitrary factor. There seems to be a sign problem in extracting of W/sub LT/ but the overall agreement is reasonable. Presently, a comparison to a microscopic calculation is being studied.