请问以下哪有错 提示是sum(a)中的a有错

Private Sub Command1_Click()
Dim a(10), i As Integer
For i = 0 To 5
a(i) = i + 10
Next i
Text2.Text = Sum(a)
End Sub
-------------------------------------------
Private Function Sum(a() As Integer) As Long
Dim i As Integer
Dim summ As Long
For i = 1 To 5
summ = summ + a(i)
Next i
Sum = summ
End Function
问题补充：
错误提示:
类型不匹配:缺少数组或用户自定义类型
光标停在Text2.Text = Sum(a)中的 a 上

Dim a(10), i As Integer
第一句有问题,很简单的问题,因为这是vb6的规定,a没有被定义为integer,被定义成variant了,只有i被定义成了integer,把这一句改成
Dim a(10) as integer, i As Integer
全部定义好类型,一切ok了,以后要注意这个问题

Text2.Text = STR(Sum(a))