sFile = Left$(sBuffer, InStr(sBuffer, vbNullChar) - 1)

Public Function MP3_Play(ByVal sFile As String, _
  ByVal sAlias As String) As Boolean
 
        Dim bResult As Boolean
 
        ' Dateinamen in DOS 8.3 Format, da z.B. Sonderzeichen
        ' wie Leerzeichen Probleme machen
        Dim sBuffer As String
        Dim lResult As Long
 
        sBuffer = Space$(255)
        lResult = GetShortPathName(sFile, sBuffer, Len(sBuffer))
 
        If lResult <> 0 Then
            sFile = Left$(sBuffer, InStr(sBuffer, vbNullChar) - 1)
 
            ' MCI öffnen
            lResult = mciSendString("open " & sFile & _
              " type MPEGVideo alias " & sAlias, 0, 0, 0)
 
            If lResult = 0 Then
                ' MP3 abspielen
                If mciSendString("play " & sAlias & _
                  " from 0", 0, 0, 0) = 0 Then
                    bResult = True
                End If
            End If
        End If
 
        MP3_Play = bResult
    End Function

        If lied1 = "leer" Then
            GoTo ml1
        End If
        MP3_Play(lied1), "MyAlias"
ml1:
        If lied2 = "leer" Then
            GoTo ml2
        End If
        MP3_Play(lied2),  "MyAlias"
ml2:
        If lied3 = "leer" Then
            GoTo ml3
        End If
        MP3_Play(lied3),  "MyAlias"
ml3:
        If lied4 = "leer" Then
            GoTo ml4
        End If
        MP3_Play(lied4), "MyAlias"
ml4:

Dim lied1 As String = TextBox1.Text
        Dim lied2 As String = TextBox2.Text
        Dim lied3 As String = TextBox3.Text
        Dim lied4 As String = TextBox4.Text