[OpenLayers-Users] select multiple layers?

[Wendell Turner]

In an environment where multiple layers have objects that
are selectable, how do they get un-selected?  That is,
in this function:
   function onPopupClose(evt) {
      selectControl.unselect(selectedFeature);
   }
how does it know which selectControl item was used for the
popup?  Does the evt object have a reference to the
selectControl?  Or does the 
        function onFeatureSelect(feature)
need to save that value?  Does the feature object have a
reference to a layer or selectControl?

Or can one selectControl span multiple layers?

Thanks,

Wendell