Function IsIntegerValue Global String sCheckValue Returns Boolean
    String sTst
    Boolean bOk
    Integer iNumChar
    Integer iCount

    Move True To bOk
    Move 0 To iCount
    Move (Length (sCheckValue)) To iNumChar
    While (bOk And (iCount < iNumChar))
        Increment iCount
        Move (Mid (sCheckValue, 1, iCount)) To sTst
        If (Not ("0123456789" Contains sTst)) Begin
            Move False To bOk
        End
    End

    Function_Return bOk
End_Function // IsIntegerValue