Selection of face's edges

hi,

i'd like to select some of face's edges in the local context. i prepared the next function, but it doesn't work well. edges are hilighted but when i try to remove some of them by means of the SHIFT mouse selection, they stay selected. is there something wrong in my code?

best regards,
adrian

bool Select_Edge (Handle(AIS_InteractiveContext) &po_AIS_Context, AIS_ListOfInteractive &o_AIS_Objects, TopoDS_Edge &o_Edge, bool b_Update_Display)
{
AIS_ListIteratorOfListOfInteractive o_iterator;

for (o_iterator.Initialize (o_AIS_Objects); o_iterator.More(); o_iterator.Next())
{
if (o_iterator.Value()->IsKind(STANDARD_TYPE(AIS_Shape)))
{
Handle(AIS_Shape) po_shape = Handle(AIS_Shape)::DownCast (o_iterator.Value()); //->Shape();

if (po_shape->HasSelection (2))//TopAbs_EDGE))
{
const Handle(SelectMgr_Selection) &po_selection = po_shape->Selection (2);//TopAbs_EDGE);
for (po_selection->Init (); po_selection->More(); po_selection->Next())
{
const Handle(SelectBasics_SensitiveEntity) &po_sel_entity = po_selection->Sensitive ();

const Handle(SelectBasics_EntityOwner) &po_basic_owner = po_sel_entity->OwnerId();

DeclareAndCast (SelectMgr_EntityOwner, po_mgr_owner, po_basic_owner);

const TopoDS_Shape &o_owner_shape = ((Handle(StdSelect_BRepOwner)&)po_mgr_owner)->Shape();

if (o_owner_shape.ShapeType()== TopAbs_EDGE)
{
const TopoDS_Edge &o_edge = TopoDS::Edge(o_owner_shape);

if (o_edge.IsSame (o_Edge))
{

const Handle(AIS_Selection) &po_cur_ais_selection = AIS_Selection::CurrentSelection();

po_cur_ais_selection->Select (po_mgr_owner);

if (po_AIS_Context->HasOpenedContext())
po_AIS_Context->HilightSelected (b_Update_Display);
else
po_AIS_Context->HilightCurrents (b_Update_Display);

return true;
}
}
}
}
}
}

return false;
}