Aim: To have only one of each character on the Return string:

```
Public Shared Function CheckForDuplicates(ByVal vCharCheck As String) As String

    Dim vDeDuplicated As String = ""
    Dim i As Integer

    For i = 1 To vCharCheck.Length ' Count length of string

        'vDeDuplicate is blank to start so will always capture first character
        'vDeDuplicate is then checked against each character in the incoming string to see if it contains this character already
        'thus deduplicting the string

        If vDeDuplicated.Contains(Mid(vCharCheck, i, 1)) Then   
            'Check the new string to see if it exists, if it does it is not allowed 
        Else
            'The character is not found so we add it
            vDeDuplicated += Mid(vCharCheck, i, 1)
        End If

    Next

    Return vDeDuplicated
End Function

```