Does anyone know why this doesn't work?
Public Class Class1
Declare Function GetUserName Lib "advapi32.dll" Alias "GetUserNameA" (ByVal lpBuffer As String, ByVal NSize As Long) As Long

Public Function SysGetUserName() As String
Dim UserName As String
Dim BufSize As Long
Dim RetCode As Long
Dim NullCharPos As Long

UserName = Space(80)
BufSize = Len(UserName)

RetCode = GetUserName(UserName, BufSize)

NullCharPos = InStr(UserName, Chr(0))

If NullCharPos > 0 Then
UserName = Left(UserName, NullCharPos - 1)
Else
UserName = ""
End If

MsgBox(UserName)
End Function
End Class