因果分析法:怎么用VB6来判断网络连接？

'窗体代码
Private Sub Form_Load()
If IsConnected = True Then
MsgBox ("ÄúÒѾ­Á¬Í¨ÁËInternet!")
End If
If IsConnected = False Then
MsgBox ("Äú»¹Ã»ÓÐÁ¬Í¨ Internet!")
End If
Unload Me
End Sub

'/£ªº¯ÊýIsConnected·µ»ØÁ¬Í¨µÄ״̬£¬Èç¹ûΪTrueÔò±íʾÒÑÁ¬Í¨£ª/

Public Function IsConnected() As Boolean
Dim TRasCon(255) As RASCONN95
Dim lg As Long
Dim lpcon As Long
Dim RetVal As Long
Dim Tstatus As RASCONNSTATUS95
TRasCon(0).dwSize = 412
lg = 256 * TRasCon(0).dwSize
RetVal = RasEnumConnections(TRasCon(0), lg, lpcon)
If RetVal <> 0 Then
MsgBox "´íÎó"
Exit Function
End If
Tstatus.dwSize = 160
RetVal = RasGetConnectStatus(TRasCon(0).hRasCon, Tstatus)
If Tstatus.RasConnState = &H2000 Then
IsConnected = True
Else
IsConnected = False
End If
End Function

'--------------------------------------------------------
’模块代码
Option Explicit
'/£ªÓйصÄAPIÉùÃ÷ºÍ¶¨Ò壪/
Public Declare Function RasEnumConnections Lib "RasApi32.dll" Alias "RasEnumConnectionsA" (lpRasCon As Any, lpcb As Long, lpcConnections As Long) As Long
Public Declare Function RasGetConnectStatus Lib "RasApi32.dll" Alias "RasGetConnectStatusA" (ByVal hRasCon As Long, lpStatus As Any) As Long
'¡¡ /£ª³£ÊýºÍ±äÁ¿µÄÉ趨£ª/
Public Const RAS95_MaxEntryName = 256
Public Const RAS95_MaxDeviceType = 16
Public Const RAS95_MaxDeviceName = 32

Public Type RASCONN95
dwSize As Long
hRasCon As Long
szEntryName(RAS95_MaxEntryName) As Byte
szDeviceType(RAS95_MaxDeviceType) As Byte
szDeviceName(RAS95_MaxDeviceName) As Byte
End Type

Public Type RASCONNSTATUS95
dwSize As Long
RasConnState As Long
dwError As Long
szDeviceType(RAS95_MaxDeviceType) As Byte
szDeviceName(RAS95_MaxDeviceName) As Byte
End Type

'------------------------------------------------------------
我用这个代码判断不了，因为明明可以上网，但是结果确实不能连接。请问哪位能解释一下上面的代码或者给出一个思路，谢谢！