New data on electromagnetic hadron form factors have triggered large theoretical and experimental efforts and inspired new ideas and several proposals at different accelerators. The possibility to achieve $Q^2$ values up to $\\simeq $ 6 GeV$^2$ and the inconsistencies among form factors extracted from polarized and unpolarized experiments suggest to search for the two-photon contribution. A calculation of radiative corrections based on the structure function method can bring the results into agreement and shows that the two photon contribution to electron proton elastic scattering is small.
| 
