编程序验证歌德巴赫猜想：任意一个大偶数 n，都能将其表示成两个素数之和。

来一个vb的：
Private Sub form_Click()
Dim N As Long, I As Long, J As Long
N = int(val(inlutbox("一个大于6的任意偶数","输入",300)
If N Mod 2 = 0 And N >= 6 Then
For I = 2 To N \ 2
If I = 2 Or Pd(I) Then
J = N - I
If Pd(J) Then
Label1.Caption = N & "=" & I & "+" & J & "符合!"
Exit Sub
End If
End If
Next
Label1.Caption = "结果: 不符合!"
Else
Text1.Text = "请输入大于或等于6的偶数!"
End If
End Sub

Function Pd(a As Long) As Boolean
Dim b As Long
For b = 2 To a - 1
DoEvents
If a Mod b = 0 Then
Pd = False
Exit For
Else
Pd = True
End If
Next
End Function