编写VB程序，在文本框Text1中输入需要产生的密码个数n，单击“确定”按钮confirm，生成n个长度为6的由大小写字母和数字0~9组成的密码，并在列表框中显示。程序运行时界面如下图所示。
为实现上述功能请在划线处填上合适代码
Private Sub confirm_Click()
Dim i As Integer, j As Integer
Dim n As Integer, m As Integer Dim k As Integer, s As String Const length=6
n=Val(Text1.Text)i=1
List1.Clear
s=""
For j=1Tolength
k=Int(Rnd()*3)+1
If k=1Then
m=Int(Rnd()*26)+1
s=s+Chr(Asc("a")+m-1)
ElseIf k=2Then
m=Int(Rnd()*26)+1
s=s+Chr(Asc("A")+m-1)
Else
m=⑴{#blank#}1{#/blank#}
s=s+Chr(Asc("0")+m-1)
EndIf
Next j
List1.AddItemStr(i)+""+s
⑵{#blank#}2{#/blank#}
Loop
End Sub
