阅读以下说明及Visual Basic程序代码，将应填入(n)上处的字句写在对应栏内。

[说明]

字符组合：程序界面如图示，在文本框Text1中输入若干个任意字符，单击“颠倒”按钮，将这些字符按相反的顺序显示在标签Lable1 中，并在标签Labs1 2处显示字符的个数。例如：输入abcabc2，显示为 2cbabca，组成字符数为4。

[Visual Basic 代码]

Private Sub cmdshow_ Click (

Dim n As Integer

Dim I As Integer

Dim str1 As String

N=Len ( Text1.Text )

For I=n To Step- 1

Str1=(1)

Next I

Labe11. Caption=Str1

End Sub

Private Sub cmdcount_ Click ( )

Dim n As Integer

Dim in As Integer

Dim i As Integer

Dim j As Integer

Dim flag As Integer

Dim str1 As Integer

Dim str2 As Integer

N=(2)

Str1 =Mid＄ ( Text1.Text, i. 1

For I =2 To n

Str2=mid＄ ( Text1,Text,I,1

M=Len (str1)

(3)

For j=1 To m

If (4) Then flag= 1; Exit For

Next j

If flag＜＞1 then str1=str1& str2

Next I

Lable2.Caption=(5)

End Sub