vb textbox输不上字，刚输完点别处，字就消失了

窗体代码如下

Private Sub Command1_Click()
If txt2 = "" Then
MsgBox "作者不能为空！", , "请重新输入"
Exit Sub
End If
adoed.Recordset.Update
adoed.Recordset.MoveLast
MsgBox "修改成功"
End Sub

Private Sub Command2_Click()
adoed.Recordset.CancelUpdate
MsgBox "取消修改成功"
adoed.Recordset.AddNew
End Sub

Private Sub Command3_Click()
Unload Me
Form4.Show
End Sub

Private Sub Form_Load()
adoed.RecordSource = "select * from writer where 作者号='" & vwid & " '"
adoed.Refresh
End Sub