Unable to set MatchKey field

If the theme's MatchSource is using an address style with Zone (US Streets with Zone, US House with Zone, and so forth), don't set the Zone to the MatchKey (aMatchKey.SetZoneKey). The following script does basic matching:

Code:
theInput = msgbox.multiinput("","",{"address","zone"},{"",""}) 
theGraphicList = av.getactivedoc.GetGraphics 
address=theInput.get(0) 
city=theInput.get(1) 
matchTheme = av.getactivedoc.FindTheme("Streets") 
aMatchSource = matchTheme.GetMatchSource 
aMatchSource.OpenIndex 
aMatchKey = MatchKey.Make(aMatchSource.GetStanRules) 
aMatchKey.AllowIntersections("us_intsc.stn", " & ") 
aMatchCase = MatchCase.Make(aMatchSource, aMatchKey) 
aMatchCase.AllowIntersections(aMatchSource, aMatchKey) 
aMatchPref = MatchPref.Make 
aMatchKey.SetKey(address) 

if (address.Contains("&").Not) ' <****** 
then ' <****** 
if (aMatchSource.HasZone) ' <****** 
then ' <****** 
aMatchKey.SetZoneKey(city) ' <****** 
end ' <****** 
end ' <****** 

numCand = aMatchSource.Search(aMatchKey,80,aMatchCase) 
if (numCand = 0) then 
av.ShowMsg(address.Proper++"not found!") 
return nil 
else 
aMatchCase.ScoreCandidates 
bestCand = aMatchCase.GetBestCand 
Location = aMatchSource.GetPoint( bestCand ) 
aMatchSource.EndMatch 
gPt = GraphicShape.Make(Location) 
theGraphicList.Add(gPt) 
end 

Note the test for the condition where the input address contains an ampersand. This would indicate the address is an intersection. If the address is not an intersection, use the SetZoneKey request. If it is an intersection, don't use this request. Also, don't use the SetZoneKey request if the MatchSource.HasZone is false; in other words, if the theme was not built with a Zone address style.