怎么出现了下标越界？？高人指点。

Private Sub Command3_Click()
Dim n As Long
Dim I As Long
Dim j As Long

Dim a(9) As Long
Dim t As Long
For I = 0 To 9
  a(I) = Rnd * 100
  Picture1.Print a(I);
Next I
n = UBound(a) - LBound(a) + 1
For I = 0 To n - 2 这里的两行代码应该是怎样的？？
For j = 0 To n - I
If a(j) > a(j + 1) Then
  t = a(j + 1)
  a(j + 1) = a(j)
  a(j) = t
End If
Next j

Next I
For I = 0 To n
Picture2.Print a(I);
Next
End Sub

a(9)是一个9个元素的数组，
怎么能用 for i=0 to9 赋值，赋10个元素，这样肯定越界