Add Parameter to a Function without affecting othere scripts using the same Function

x = add(10,15,Array(10,15))
MsgBox x

Function add(a,b,c)

    If IsArray(c) Then
        t = 0
        For i = 0 To ubound(c)
            t = t + c(i)
        Next
        Else
        t = c
    End If
    r = a+b+t
    add = r

End Function


...