boolean operations( CUT )

hello,

I tried to make an extraction of a solid out of an other solid(!?) (of revolution!!!) ... the result is incorrect ... what is missing from the bellow code?

thanks...

TopoDS_Shape theBox = BRepPrimAPI_MakeSphere(gp_Pnt(70,0,70),170);

TopoDS_Edge E1 = BRepBuilderAPI_MakeEdge(gp_Pnt(0., 0., 0.),gp_Pnt(100., 0., 0.)); TopoDS_Edge E2 = BRepBuilderAPI_MakeEdge(gp_Pnt(100., 0., 0.), gp_Pnt(75.,50., 0.)); TopoDS_Edge E3 = BRepBuilderAPI_MakeEdge(gp_Pnt(75.,50., 0.), gp_Pnt0.,50., 0.)); TopoDS_Edge E4 = BRepBuilderAPI_MakeEdge(gp_Pnt(0.,50., 0.),gp_Pnt(0., 0., 0.)); TopoDS_Wire W = BRepBuilderAPI_MakeWire(E1,E2,E3,E4);

axe = gp_Ax1(gp_Pnt(0.,0.,0.),gp_Dir(0.,1.,0.));

TopoDS_Shape S3 = BRepPrimAPI_MakeRevol(W,axe);

TopoDS_Shape ShapeCut = BRepAlgoAPI_Cut( S3, theBox );