VB题目求答案！
232 4.100m 6km-8km 500m
急求VB高手帮我做一下这个程序填空题，很急！！！如果做得好我追加悬赏！
Private Sub Form_Click()
Dim ch$, n1%, n2%, n3%
n1 = 0
n2 = 0
n3 = 0
ch = InputBox("请输入一个字符")
'**********SPACE**********
Do While ch "?"
Select Case ch
Case "a" To "z"
n1 = n1 + 1
'**********SPACE**********
Case "A" to "Z"
n2 = n2 + 1
Case "0" To "9"
n3 = n3 + 1
End Select
ch = InputBox("请输入一个字符")
'**********SPACE**********
loop
Print n1, n2, n3
End Sub