combobox多选框选择

vb登陆用户多选框自动记录数据库中用户信息，将数据库中对应用户名信息显示在多选框中

Private Sub Form_Load()

     Dim i As Integer
    Dim cnn As ADODB.Connection
  Dim my_recordset As ADODB.Recordset
  Dim connect_string As String
  Dim statestring As String
  Set cnn = New ADODB.Connection
  Set my_recordset = New ADODB.Recordset
  '连接Access数据库
  connect_string = "DSN=medic_lib97;UID=;PSW="
  cnn.Open connect_string
  Select Case cnn.State
    Case adStateClose
         statestring = "adStateClosed"
    Case adStateOpen
         statestring = "adStateOpen"
  End Select
  '显示连接的状态
  MsgBox "连接成功！", , statestring
  
     my_recordset.Open "select id from user", cnn, adOpenKeyset, adLockOptimistic
    For i = 1 To my_recordset.RecordCount
        Combo1.AddItem Trim(my_recordset(0) & "")
        my_recordset.MoveNext
    Next
    my_recordset.Close
End Sub