' Return True if a string is a valid name for a Visual Basic variable or ' procedure.' This function turns to be useful when writing add-ins that generate code.' The optional argument specifies whether the dot character is accepted.Function ValidateVBName(ByVal VBName As String, Optional ByVal acceptDots As _    Boolean = False) As Boolean    Dim i As Long    ' reject null strings or strings that are too long    If VBName Is Nothing OrElse VBName.Length = 0 OrElse VBName.Length > 255 _        Then        Exit Function    ElseIf VBName.IndexOf("..") >= 0 Then        ' two consecutive dots aren't valid        Exit Function    End If    ' create the regular expression    ' note that ^ is the beginning of string, $ is end of string    Dim pattern As String = "^[A-Z_][A-Za-z0-9_]*$"    If acceptDots Then        pattern = "^[A-Z_][A-Za-z0-9_.]*$"    End If    Dim re As New Text.RegularExpressions.Regex(pattern, _        Text.RegularExpressions.RegexOptions.IgnoreCase)    ' return True if it is a perfect match    Return re.IsMatch(VBName)End Function