Email Validation

				Private Function erGyldigEpost(ByVal strEpost As String) As Boolean
Dim bForbiAlfaKrøll As Boolean = False
Dim bForbiDomene As Boolean = False
Dim strDomain As String = ""
Dim iUserString As Integer = 0
Dim iHostString As Integer = 0
For Each c As Char In strEpost
If bForbiAlfaKrøll = False Then
If c = "@" Then
bForbiAlfaKrøll = True
Else
If Char.IsLetterOrDigit(c) = False And c <> "." Then
Return False' fant symbol eller noe lignende før alfakrøll
Exit Function
Else
iUserString = iUserString + 1
End If
End If
ElseIf bForbiAlfaKrøll = True And bForbiDomene = False Then
If c = "." Then
bForbiDomene = True
Else
If Char.IsLetterOrDigit(c) = False Then
Return False' fant symbol eller noe lignende etter alfakrøll
Exit Function
Else
iHostString = iHostString + 1
End If
End If
ElseIf bForbiDomene = True Then
If Char.IsLetter(c) = True Then
strDomain = strDomain & c
Else
Return False' fant symbol eller noe lignende i toppdomenet.
Exit Function
End If
End If
Next
If iUserString >= 2 And iHostString >= 2 And erGyldigDomene(strDomain) = True Then
Return True ' username er lengre enn 2 chars, hostname er lengre enn 2 chars og det er et gyldig toppdomene.
Else
Return False' for kort username/hostname eller ugyldig toppdomene.
End If
End Function
Private Function erGyldigDomene(ByVal strDomene As String) As Boolean
Dim wwwClient As New Net.WebClient
Dim strDomains As String = wwwClient.DownloadString("http://en.wikipedia.org/wiki/List_of_Internet_top-level_domains")
Return CBool(InStr(strDomains, "." & strDomene) <> 0)
End Function