VB 阵列索引超出范围，怎解!!~

Dim a As String, b() As String
Open "D:\2.txt" For Input As #1
Open "D:\3.txt" For Output As #2

While Not EOF(1)

Line Input #1, a

b = Split(a, " ")

If b(0) = "[BlockData]" Then

msgbox b(0)

ElseIf b(0) = "IDNUM" Then

msgbox b(0)

ElseIf b(5) <> "" Then 跑到这段资料，跑到尾没资料了就报错!!??
怎麼去判断数组内的资料没了就离开呢?
msgbox b(5) & b(7)

Print #2, b(5), b(7)

ElseIf b(5) <> b(5) Then

GoTo ED

End If

Wend

ED:

Close #2
Close #1

msgbox "作业完成，档案为3.TXT"

b = Split(a, " ")的时候，如果分组不够，后面就不产生了，访问b(5)就会失败，而不是内容为空
需要知道有没有b(5)，要写成：elseif UBound(b)〉=5 then
另外是不是有b（7）也要判断if UBound(b)〉=7
否则访问b(7)也抱错

使用数组公式 假如数据在a1：f3 =small(if(a1:f3=h5,row(a1:f3),0),18) & "," & small(if(a1:f3=h5,column(a1:f3),0),18) 按ctrl+shift+enter结束