求教“运行时错误3704，对象关闭时不允许操作”的解决

Private Sub btnCal_Click()
    Dim rst As New ADODB.Recordset    
    Set rst = Me.Recordset

    MsgBox rst.RecordCount

End Sub

Private Sub Form_Load()    
    Dim cn As New ADODB.Connection
    Dim rs As New ADODB.Recordset
    Set cn = CurrentProject.Connection
    rs.Open "SELECT * FROM Customers", cn, adOpenKeyset, adLockOptimistic
    Set Me.Recordset = rs
    rs.close
    set rs=nothing

    cn.close

    set cn=nothing
End Sub

运行这段代码时，总是提示“运行时错误3704，对象关闭时不允许操作”，不知道哪里出了问题，求大神指点。me.recordset已在窗体加载事件中设成ADO类型。