对象变量或 With 块变量没有设置（错误 91）？怎么回事？如何解决呢？求救大神

Public Function BtnDisplayZZZ()


    Dim btn As Label, H As Integer
    Dim SQL As String
    Dim db As Database
    Dim rec As DAO.Recordset
    Dim bTop As Integer
    
    For X = 1 To 20
        Set btn = Me.Controls("ABT" & Format(X, "00"))
        btn.Visible = False
    Next
    Set db = CurrentDb()
    If BTZZZ > 6 Then
        MenuBox.Visible = False
        Exit Function
    End If
    
    SQL = "SELECT Menutbl.Button, Menutbl.Label, Left([button],1) AS btn FROM Menutbl WHERE (((Menutbl.Label) Is Not Null) AND ((Left([button],1))=" & BTZZZ & "));"
    
    Set rec = db.OpenRecordset(SQL, dbOpenDynaset)
    Do While Not rec.EOF
        H = H + 1
        Set btn = Me.Controls("ABT" & Right(rec(0), 2))
    
        If H = 1 Then
            bTop = 1120
        Else
            bTop = bTop + 330
        End If
        
        btn.Visible = True
        btn.Top = bTop
        btn.Caption = rec(1)
        rec.MoveNext
    Loop
    
    MenuBox.Visible = True
    MenuBox.Height = BoxH(H)
    rec.Close
    Set rec = Nothing
    Set db = Nothing
    


End Function