VB的编程题关于质数的！

Private Sub Command1_Click()
Dim I As Integer, N As Integer, x As Integer
N = Val(InputBox("输入范围"))
For x = 2 To N-1
For I = 2 To x - 1
If x Mod I = 0 Then Exit For
Next
If I >= x Then Print x
Next
End Sub

Function isprime(Num As Long) As Boolean
If Num < 2 Then isprime = False: Exit Function

Dim i As Long

For i = 2 To Sqr(Num)
If (Num Mod i) = 0 Then
isprime = False
Exit Function
End If
Next i

isprime = True
End Function

Private Sub Command1_Click()
Dim i As Long
Dim n As Long

n = CLng(InputBox("输入一个整数", "输入"))

For i = 2 To n
If isprime(i) Then
Print i
End If
Next i

End Sub