  As GRBs trace the high-z Universe, there is a non-negligible probability of a
lensing effect being imprinted on the lightcurves of the bursts. We propose to
search for lensed candidates with a cross-correlation method, by looking at
bursts days to years apart coming from the same part of the sky. We look for
similarities and hypothesize a Singular Isothermal Sphere (SIS) model for the
lens. A lensed pair would enable us to constrain the mass of the lensing
object. Our search did not reveal any gravitationally lensed events.
