  We discussed methods used by the PHENIX to constrain the flow background in
the two particle jet correlation. Both the background level and elliptic flow
can be reliably decomposed from the jet contribution. We also studied the
non-flow contribution to the reaction plane elliptic flow due to dijets. We
found the jet bias is negligible in PHENIX, when the reaction plane is measured
at Beam Beam Counter acceptance ($3<|\eta|<4$).
