STUFF String Equivalent

[SupDog]

I have city and state in one field and I need to add a comma after the city.

Dallas TX

Little Rock AR

I tried using this: IF(wildmatch(Location,'* * *'),Mid(Location, 0, Len(Location) - index(Location,' ',2)) & ', ' & Mid(Location,index(Location,' ',2)),Mid(Location, 0, Len(Location) - index(Location,' ',2)) & ', ' & Mid(Location,index(Location,' ',1)))

But that gives me

, TX

,Rock AR

Can you help me find where I'm off?  Or is there an easier way to go about this?

[sunny_talwar]

May be this

=Left(FieldName, Index(FieldName, ' ', -1) - 1) & ', ' & SubField(FieldName, ' ', -1)