INT B3 - ZIPKEY - GET VALUES NEEDED TO SAVE ZIPKEY CONTEXT                      
	AH = 7Bh
Return: BL = maximum number of characters for a city name
	BH = ZIPKEY state code for last city-name search, or FFh if none
	CX:DX = internal code identifying last city search
	AX destroyed
SeeAlso: AH=7Ch