The function below will return the user name for the logged on user, works in both Windows NT and Windows95/98.

Public Declare Function GetUserName Lib "advapi32.dll" _
    Alias "GetUserNameA" (ByVal lpBuffer As String, nSize As Long) As Long

Function ReturnUserName() As String
' returns the NT Domain User Name
Dim rString As String * 255, sLen As Long, tString As String
    tString = ""
    On Error Resume Next
    sLen = GetUserName(rString, 255)
    sLen = InStr(1, rString, Chr(0))
    If sLen > 0 Then
        tString = Left(rString, sLen - 1)
    Else
        tString = rString
    End If
    On Error GoTo 0
    ReturnUserName = UCase(Trim(tString))
End Function

ActiveUserName = Application.UserName