我是新手不知道我的下列代码错在哪里

Private Sub Command1_Click()
Dim i As Integer
Dim j As Integer
Dim temp As person
Dim a(3) As person

  For i = 1 To 2

   For j = i + 1 To 3
    If a(j).name < a(i).name Then     提示我这句错误说对象变量或with 未被设置
     temp = a(i)
     a(i) = a(j)
     a(j) = temp
    End If
   Next j
  Next i
For i = 1 To 3
Set a(i) = New person

  a(i).name = "南砼公司" + CStr(i)
  a(i).address = "湖滨北路" + CStr(i)
        Grid1.Row = i
        Grid1.Col = 0
        Grid1.Text = CStr(i)

        Grid1.Row = i
        Grid1.Col = 1
        Grid1.Text = a(i).name

        Grid1.Row = i
        Grid1.Col = 2
        Grid1.Text = a(i).address
  Next i

End Sub --------------------编程问答-------------------- Set a(i) = New person

person是类吧,New --------------------编程问答-------------------- 我也是新手！很少用数组！ --------------------编程问答-------------------- If a(j).name < a(i).name 之前，必须为a(n)创建对象

for i=0 to 3
set a(i)=new person
next --------------------编程问答--------------------



Dim temp As person

Dim a(3) As person

person是啥东西。VB里面没有这东西。

补充：VB ,  基础类