how to use the ais_relation's derivates?

dear

who can help me with checking some pieces codes which use ais_parallelrelation to show the paralleling relation of two planes?

i do this :
gp_Pnt pt=first.Location();
gp_Dir dir=first.Axis().Direction();
Handle(Geom_Plane) gp=GC_MakePlane(pt,dir);

Handle(AIS_ParallelRelation) parrelation=
new AIS_ParallelRelation(m_FixedFeature,m_FloatedFeature,
gp);

myContextView->Display(parrelation,false);

but exception raised.

please help me