（加试题）小李编写 VB 程序，功能如下：单击“生成数组”按钮 Command1，则随机生成 13 个取值范围是 1～13 的正整数，分别存储到数组 a 中，对数组 a 的元素进行升序排列，并在标签label1 中显示；再单击“连续数”按钮 Command2，则在排序后的数组 a 中查找连续个数最多(忽略重复数值)的一组数值（即：连续数），若有两组连续数个数一样多，则取数值小的一组，

将连续数显示在标签 label2 中。运行界面如图所示。

若实现上述功能的程序如下，请在划线处填写合适代码，使程序正常运行。
Dim a(1 To 13) As Integer
Dim n As Integer
Private Sub Command1_Click()
Dim i As Integer, s As String, j As Integer
Randomize
n = 13
For i = 1 To n
a(i) = Int(Rnd * 13) + 1
Next i
For i = 1 To n - 1
For j = i + 1 To n
If a(j) < a(i) Then
t = a(j): a(j) = a(i): a(i) = t
End If
Next j
Next i
s = ""
For i = 1 To n
s = s + Str(a(i))
If ________　Then s = s + ","　
Next i
Label1.Caption = s
End Sub
Private Sub Command2_Click()
Dim i As Integer, j As Integer
Dim t As Integer, k As Integer
Dim max As Integer　'存储连续数个数最大值
Dim begin As Integer　'存储连续数开始的数值
k = 1
max = 1
For i = 2 To 13
If a(i) = a(i - 1) + 1 Or a(i) = a(i - 1) Then
If ____________　 Then k = k + 1
If k > max Then
max = k
begin = ____________　　
End If
Else
k = 1
End If
Next i
s = ""
For j = begin To begin + max - 1
s = s + Str(j)
Next j
Label2.Caption = s
End S