  Within the mSUGRA model, the observability of the decay of the next to
lightest neutralino into leptons and the lightest neutralino has been studied
using a full simulation of the CMS detector. The final state signature consists
of two opposite sign leptons, several hard jets and missing transverse energy.
The expected precision of the measurement of the dilepton mass edge is reported
for 1 fb^-1 of data, including systematic and statistic uncertainties,
comparing two benchmark points with different signatures.
