Probleme liste deroulante

Private Sub ComboBox1_Change()
  [B4] = Me.ComboBox1
End Sub

Private Sub ComboBox1_DropButtonClick()
  Dim temp()
  Set f = Sheets("2012")
  temp = Application.Transpose(f.Range("F3:F" & f.[F65000].End(xlUp).Row))
  Call Tri(temp(), LBound(temp), UBound(temp))
  Me.ComboBox1.List = temp
End Sub

Sub Tri(a(), gauc, droi) ' Quick sort
  ref = a((gauc + droi) \ 2)
  g = gauc: d = droi
  Do
    Do While a(g) < ref: g = g + 1: Loop
    Do While ref < a(d): d = d - 1: Loop
    If g <= d Then
       temp = a(g): a(g) = a(d): a(d) = temp
       g = g + 1: d = d - 1
     End If
   Loop While g <= d
   If g < droi Then Call Tri(a, g, droi)
   If gauc < d Then Call Tri(a, gauc, d)
End Sub