有谁知道用C#编程控制拨号上网的技术吗？
我想自己编码实现ADSL拨号上网     C#
请高手赐教

------解决方案--------------------
调用代码:
RASDisplay ras = new RASDisplay();
ras.Disconnect();//断线
ras.Connect( "adsl ");//拨号,adsl是宽带连接的名称


//ADSL自动断拨号类
//=====================================
using System;
using System.Runtime.InteropServices;
public struct RASCONN
{
public int dwSize;
public IntPtr hrasconn;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst=257)]
public string szEntryName;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst=17)]
public string szDeviceType;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst=129)]
public string szDeviceName;
}

[StructLayout(LayoutKind.Sequential,CharSet=CharSet.Auto)]
public struct RasStats
{
public int dwSize;
public int dwBytesXmited;
public int dwBytesRcved;
public int dwFramesXmited;
public int dwFramesRcved;
public int dwCrcErr;
public int dwTimeoutErr;
public int dwAlignmentErr;
public int dwHardwareOverrunErr;
public int dwFramingErr;
public int dwBufferOverrunErr;
public int dwCompressionRatioIn;
public int dwCompressionRatioOut;
public int dwBps;
public int dwConnectionDuration;
}

[StructLayout(LayoutKind.Sequential,CharSet=CharSet.Auto)]
public struct RasEntryName
{
public int dwSize;
//[MarshalAs(UnmanagedType.ByValTStr,SizeConst=(int)RasFieldSizeConstants.RAS_MaxEntryName + 1)]
public string szEntryName;
//#if WINVER5
// public int dwFlags;
// [MarshalAs(UnmanagedType.ByValTStr,SizeConst=260+1)]
// public string szPhonebookPath;
//#endif
}
public class RAS

{


[DllImport( "Rasapi32.dll ", EntryPoint= "RasEnumConnectionsA ",
SetLastError=true)]

internal static extern int RasEnumConnections
(
ref RASCONN lprasconn, // buffer to receive connections data
ref int lpcb, // size in bytes of buffer
ref int lpcConnections // number of connections written to buffer
);


[DllImport( "rasapi32.dll ",CharSet=CharSet.Auto)]
internal static extern uint RasGetConnectionStatistics(
IntPtr hRasConn, // handle to the connection
[In,Out]RasStats lpStatistics // buffer to receive statistics
);
[DllImport( "rasapi32.dll ",CharSet=CharSet.Auto)]
public extern static uint RasHangUp(
IntPtr hrasconn // handle to the RAS connection to hang up
);

[DllImport( "rasapi32.dll ",CharSet=CharSet.Auto)]
public extern static uint RasEnumEntries (
string reserved, // reserved, must be NULL
string lpszPhonebook, // pointer to full path and
// file name of phone-book file
[In,Out]RasEntryName[] lprasentryname, // buffer to receive
// phone-book entries
ref int lpcb, // size in bytes of buffer
out int lpcEntries // number of entries written
// to buffer
);

[DllImport( "wininet.dll ",CharSet=CharSet.Auto)]
public extern static int InternetDial(
IntPtr hwnd,
[In]string lpszConnectoid,
uint dwFlags,
ref int lpdwConnection,
uint dwReserved
);

public RAS()
{