Private Sub Command1_Click()
On Error GoTo error1
CommonDialog1.Filter = "文本文件(txt格式)|*.txt|"
CommonDialog1.ShowOpen
Text1.Text = Loadtext(CommonDialog1.FileName)
Label1.Caption = CommonDialog1.FileName
Exit Sub
error1:
Exit Sub
End Sub

Private Sub Command2_Click()
Text1.Text = Loadtext()
Label1.Caption = ""
End Sub

Private Sub Command3_Click()
End
End Sub
（打开文本文件，清除文本框内容，但运行时说编译错误，子程序或函数未定义。 请大虾指导）