Response.ContentType = "text/xml"

Dim quantity, unitPrice
Dim discount, extPrice

On Error Resume Next

quantity = Request.QueryString.Item("quantity")
unitPrice = Request.QueryString.Item("unitPrice")

discount = QuantityDiscount(quantity)
extPrice = (CDbl(quantity) * CDbl(unitPrice))*(1 - (discount/100))

If Err.number <> 0 Then
   Response.Write (ErrorXML())
Else
   Response.Write (SuccessXML(discount, extPrice))
End If