Public Declare Function InternetGetConnectedState _
                         Lib "wininet.dll" (lpdwFlags As Long, _
                                            ByVal dwReserved As Long) As Boolean
Function IsConnected() As Boolean
    Dim Stat As Long
    IsConnected = (InternetGetConnectedState(Stat, 0&) <> 0)
End Function
Sub Test()
    If IsConnected = True Then
        MsgBox "İnternet bağlıdır", vbInformation
    Else
        MsgBox "İnternet bağlı değildir.", vbExclamation
    End If
End Sub