How to validate a phone number

[LouLou]

I have this code for checking to see if a phone
number is entered as numbers but it is not working
could someone tell me why?

If isempty(Phone) then
PhoneIsOkay = false
PageIsOkay = false

else
If len(Phone)<>8then
PhoneIsOkay = false
PageIsOkay = false

i = 1
While i < 8 'there are eight spaces that you want to check

Select Case i
Case 1,2,3 ' the positions in the string that should be numbers
If Not IsNumeric(mid(Phone,i,1)) then 'Check the format

PageIsOkay = false
End If

Case 4 'check that middle for a dash
If IsNumberic(mid(Phone, i, 1)) then
PageIsOkay =false

End If

Case 5,6,7 ' the positions in the string that should be numbers
If Not IsNumeric(mid(Phone,i,1)) then 'Check the format

PageIsOkay = false
End If
End Select
i= i+1
Wend
End If
End If




Thanks
Louise