下面一段程序的功能是，单击命令按钮后将D盘temp 目录下的staff.txt 文件内容读出，并在文本框Text1中显示出来。请填空。
Private Sub Command1_ Click()
Dim Line As String, FileNo As Integer
Dim People As String
FileNo = FreeFile
Open "D:\temp\staff.txt" For Input As ______
DO While Not ______
Line Input #FileNo, Line
People = People + Line + Chr(13) + Chr(10)
Loop
Text1.Text = People
End Sub