vb 循环问题

[twtiqfn]

我用access数据库，里面有编号为0—100的记录，我想随机的筛选记录，（我想随机选10条，再选10条的话，就是从剩下的90中随机选）我的数据库有个字段flag初始化为0，当选中了一条后，程序将会置1

循环语句却有错误：
mCount = rs.RecordCount
Randomize Timer
Number = Val(Text1.Text)
For k = 1 To Number
lCurRow = Int(Rnd * mCount) + 1 '产生一个随机数
rs.Move lCurRow - 1 '定位
Do While rs!flag = 1
lCurRow = Int(Rnd * mCount) + 1
rs.Move lCurRow - 1 '定位
MsgBox "已存在！", vbExclamation, "提示"
Loop
a = rs!bh
db.Execute ("update shiyan set flag=1 where bh=" & a & "")
List1.AddItem rs!bh
List1.AddItem rs!xm
Label4.Caption = rs!xm
n = n + 1
Label5.Caption = n

Next k
rs.Close
for循环和do while循环虽没语法错误，但实现不了功能。do while会出现死循环，请大家帮忙啊

[li163]

mCount = rs.RecordCount
Randomize Timer
Number = Val(Text1.Text)

For k = 1 To Number
    lCurRow = Int(Rnd * mCount) + 1 '产生一个随机数
    rs.Move lCurRow - 1 '定位
    
    Do While Not rs!flag = 1
        MsgBox "已存在！", vbExclamation, "提示"
        lCurRow = Int(Rnd * mCount) + 1
        rs.movefirst
        rs.Move lCurRow - 1 '定位
    Loop
    
    a = rs!bh
    db.Execute ("update shiyan set flag=1 where bh=" & a & "")
    List1.AddItem rs!bh
    List1.AddItem rs!xm
    Label4.Caption = rs!xm
    n = n + 1
    Label5.Caption = n
Next k

rs.Close

[li163]

mCount = rs.RecordCount
Randomize Timer
Number = Val(Text1.Text)

For k = 1 To Number
lCurRow = Int(Rnd * mCount) + 1 '产生一个随机数
rs.Move lCurRow - 1 '定位

Do While Not rs!flag = 1
MsgBox "已存在！", vbExclamation, "提示"
lCurRow = Int(Rnd * mCount) + 1
rs.movefirst
rs.Move lCurRow - 1 '定位
Loop

a = rs!bh
db.Execute ("update shiyan set flag=1 where bh=" & a & "")
List1.AddItem rs!bh
List1.AddItem rs!xm
Label4.Caption = rs!xm
n = n + 1
Label5.Caption = n
Next k

rs.Close

[king06]

    mCount = Rs.RecordCount
    Randomize Timer
    Number = Number
    For k = 1 To Number
        Rs.Requery
        Rs.Filter = "flag<>1"
        mCount = Rs.RecordCount
        
        If mCount = 0 Then Exit For
        lCurRow = Int(Rnd * mCount) + 1 '产生一个随机数
        Rs.Move lCurRow - 1 '定位
        
        a = Rs!bh
        List1.AddItem Rs!bh
        List1.AddItem Rs!xm
        Label4.Caption = Rs!xm
        n = n + 1
        Label5.Caption = n
                
        Cn.Execute ("update shiyan set flag=1 where bh=" & a & "")  '字符型的需加单引号 bh='" & a & "' "
    Next