Function IsPrivateIp(sIpAddress)
 ' Given IP string, checks whether it is a private address
 ' DOES NOT CHECK FOR VALID IP FORM
 ' Use IsValidIp to check validity
 ' Checks for STRICT private addresses;
 ' does not guess about common misuse such as 192.0 nets
 Dim aTmp
 IsPrivateIp = False
 aTmp = split(sIpAddress,".")
 ' Is it a class 10 network?
 If aTmp(0) = 10 Then IsPrivateIp = True
 ' If not a 10, is it a 172 private address?
 If aTmp(0) = 172 Then
  If ( aTmp(1)>15 )  And ( aTmp(1)<32 ) Then IsPrivateIp = True
 End If
 ' If neither of the above, is it a 192.168 IP?
 If ( aTmp(0)=192 )  And ( aTmp(1)=168 ) Then IsPrivateIp = True
End Function