We consider a nonlinear Schrodinger equation (NLS) with a very general nonlinear term and with a trapping delta potential on the line. We then discuss the asymptotic behavior of all its small solutions, generalizing a recent result by Masaki, Murphy, and Segata [Anal. PDE, to appear] by means of virial-like inequalities. We give also a result of dispersion in the case of defocusing equations with a nontrapping delta potential.
