Function StanjeP(SifraP As String)
Dim Db As Database
Dim Rs As Recordset
Dim SQL As String
Dim Ulaz As Single, Izlaz As Single

Set Db = CurrentDb

SQL = "SELECT Sum(detalji.kulaz) AS UlazS, Sum(detalji.kizlaz) AS IzlazS " _
    & "FROM detalji " _
    & "WHERE proizvod='" & SifraP & "'"
Set Rs = Db.OpenRecordset(SQL)
If Rs.RecordCount > 0 Then
Ulaz = Nz(Rs.Fields(0), 0)
Izlaz = Nz(Rs.Fields(1), 0)
StanjeP = Ulaz - Izlaz
Else
StanjeP = 0
End If
End Function