Checking An E-mail Address Is Correct !!

Hello,

I have received the following code to verify that an e-mail address is correctly typed into a text box to be passed into an Access 97 table.

The code runs fine in VB 6 but I also need it to run in VB 5. When I run the code in VB 5 I get the following error message: "Complie Error" "Sub or Function Not Defined"

then when I click 'debug' the following piece of code is highlighted within the module code: InStrRev

I would greatly appreciate any help, links or code as to why this is happennig or even a way of getting around it within VB 5. The code I am using is below...

Thanks,
Andy.............

Code:

---


 Function checkValidEmail(theAddress) As Boolean
        'http://www.4guysfromrolla.com/webtech/051999-1.shtml
        On Error GoTo ExitFalse

        ' checks for a valid email
        ' returns false for invalid addresses
        Dim atCnt
        checkValidEmail = True

        ' chk length
        If Len(theAddress) < 5 Then
        ' [email protected] should be the shortest an
        ' address could be
        checkValidEmail = False

        ' chk format
        ' has at least one "@"
        ElseIf InStr(theAddress, "@") = 0 Then
        checkValidEmail = False

        ' has at least one "."
        ElseIf InStr(theAddress, ".") = 0 Then
        checkValidEmail = False

        ' has no more than 3 chars after last "."
        ElseIf Len(theAddress) - InStrRev(theAddress, ".") > 3 Then
        checkValidEmail = False

        ' has no "_" after the "@"
        ElseIf InStr(theAddress, "_") <> 0 And _
            InStrRev(theAddress, "_") > InStrRev(theAddress, "@") Then
            checkValidEmail = False

            Else
            ' has only one "@"
            atCnt = 0
            For i = 1 To Len(theAddress)
            If Mid(theAddress, i, 1) = "@" Then
            atCnt = atCnt + 1
            End If
            Next

            If atCnt > 1 Then
            checkValidEmail = False
            End If

            ' chk each char for validity
            For i = 1 To Len(theAddress)
            If Not IsNumeric(Mid(theAddress, i, 1)) And _
            (LCase(Mid(theAddress, i, 1)) < "a" Or _
            LCase(Mid(theAddress, i, 1)) > "z") And _
            Mid(theAddress, i, 1) <> "_" And _
            Mid(theAddress, i, 1) <> "." And _
            Mid(theAddress, i, 1) <> "@" And _
            Mid(theAddress, i, 1) <> "-" Then
            checkValidEmail = False
            End If
            Next
            End If

            Exit Function

ExitFalse:

            checkValidEmail = False
            Exit Function

End Function

---

[Edited by AndyCapp on 04-07-2000 at 11:10 AM]

I don't have VB6 installed and don't have the help for taht function, but as i can see the function (implemented in VB6) should be something like this:


Function InStrRev(Str As String, ToFind As String)
Dim i As Integer
For i = Len(Str) To 1 Step -1
If Mid$(Str, i, 1) = ToFind Then Exit For
Next i
InStrRev = i
End Function

If you see, it's similar to the InStr() function, but it starts from the back. That's why the "Rev", from Reverse I guess.

I forgot to tell you this... but if you didn't understand it, you should place the code onto your project, and would work fine. However, the function posted before was right for this project, I guess it should be like this one (providing that the TextToFind may not be one character long):

Function InStrRev(Str As String, ToFind As String)
Dim i As Integer
For i = Len(Str) To 1 Step -1
If Mid$(Str, i, Len(ToFind)) = ToFind Then Exit For
Next i
InStrRev = i
End Function