Auto Interenet Disconnection

Im trying to write a program that will AutoConnect to the internet(like Internet Explore for example).
But more important is for the program to AutoDisconnect from the internet as it's closed(under the assumption that no othere program is currently using the internet connection) for example - IE disconnects at closing.
I was wondering is there and API command thar can do it.

[terebi]

If you look hard enough, somwhere on this site, probably under internet programming, there is a program that does exactly what you are looking for. Hopefully this post isn't too late to be of use

Disconnect from the Internet:

Public Const RAS_MAXENTRYNAME As Integer = 256
Public Const RAS_MAXDEVICETYPE As Integer = 16
Public Const RAS_MAXDEVICENAME As Integer = 128
Public Const RAS_RASCONNSIZE As Integer = 412
Public Const ERROR_SUCCESS = 0&

Public Type RasEntryName
    dwSize As Long
    szEntryName(RAS_MAXENTRYNAME) As Byte
End Type

Public Type RasConn
    dwSize As Long
    hRasConn As Long
    szEntryName(RAS_MAXENTRYNAME) As Byte
    szDeviceType(RAS_MAXDEVICETYPE) As Byte
    szDeviceName(RAS_MAXDEVICENAME) As Byte
End Type

Public Declare Function RasEnumConnections Lib _
"rasapi32.dll" Alias "RasEnumConnectionsA" (lpRasConn As _
Any, lpcb As Long, lpcConnections As Long) As Long

Public Declare Function RasHangUp Lib "rasapi32.dll" Alias _
"RasHangUpA" (ByVal hRasConn As Long) As Long            
Public gstrISPName As String
Public ReturnCode As Long
            
Procedure
Public Sub HangUp()
Dim i As Long
Dim lpRasConn(255) As RasConn
Dim lpcb As Long
Dim lpcConnections As Long
Dim hRasConn As Long
lpRasConn(0).dwSize = RAS_RASCONNSIZE
lpcb = RAS_MAXENTRYNAME * lpRasConn(0).dwSize
lpcConnections = 0
ReturnCode = RasEnumConnections(lpRasConn(0), lpcb, _
lpcConnections)

If ReturnCode = ERROR_SUCCESS Then
    For i = 0 To lpcConnections - 1
        If Trim(ByteToString(lpRasConn(i).szEntryName)) _
            = Trim(gstrISPName) Then
            hRasConn = lpRasConn(i).hRasConn
            ReturnCode = RasHangUp(ByVal hRasConn)
        End If
    Next i
End If

End Sub

Public Function ByteToString(bytString() As Byte) As String
Dim i As Integer
ByteToString = ""
i = 0
While bytString(i) = 0&
ByteToString = ByteToString & Chr(bytString(i))
i = i + 1
Wend
End Function
            
Using the HangUp Procedure
Once you have copied all required code into your project, you can hang up all connections to the telephone network by calling the procudure HangUp:

Call HangUp

Connect to the Internet:

Dim res
res = Shell("rundll32.exe rnaui.dll,RnaDial " _
& "connection_name", 1)