请根据算法将下列程序补充完整。
Function prime(a As Integer)As Boolean
Dim j As Integer
prime=True
j=2
Do While prime And j<=a\2
If a Mod j=0 Then
prime=False
Exit Do
End If
Loop
End Function
Private Sub Command1_Click( )
Dim i As Integer, a As Integer, b As Integer
Dim count As Integer
a=Val(Text1.Text)
b=Val(Text2.Text)
For i=a To b
If=True Then
List1.AddItem Str(i)
count=count + 1
End If
Next i
Label1.Caption=“素数共有” + Str(count) + “个!”
End Sub