;
function offset,base,popup
;
; Return 2-element vector with x and y offset for popup such that 
;   its upper right corner will match the upper left corner of
;   the base (i.e., position the popup to the left of the base)
;
widget_control,base,tlb_get_offset=base_offset
widget_control,popup,tlb_get_size=popup_size
return,[base_offset(0)-popup_size(0)-10, base_offset(1)]
end