>

>   WHERE
>         Upper(First)=Upper(@First) AND
>         Upper(Last)=Upper(@Last) AND
>         Upper(Address)=Upper(@Address) AND
>         Upper(City)=Upper(@City) AND
>         Upper(State)=Upper(@State) AND
>         Upper(Zip)=Upper(@Zip) AND
>         Upper(Country)=Upper(@Country) AND
>         Upper(Number)=Upper(@Number) AND
>         Upper(Street)=Upper(@Street) AND
>         Upper(Unit)=Upper(@Unit)
>      RETURN(0)
>

I usually wrap the parameter in an IIF(EMPTY(FieldName), .T., [condition]).

Chris.