windows mobile 关闭gprs连接

unsigned int CloseRasGPRSConnections()
{
     int index; // An integer index
     DWORD dwError, dwRasConnSize, dwNumConnections; // Number of connections found
     RASCONN RasConn[20]; // Buffer for connection state data,Assume the maximum number of entries is 20.
    BOOL RETURN_VALUE=0;
    WCHAR *MySelectNetName;

     // Assume no more than 20 connections.
     RasConn[0].dwSize = sizeof (RASCONN);
     dwRasConnSize = 20 * sizeof (RASCONN);

     // Find all connections.
     if (dwError = RasEnumConnections (RasConn, &dwRasConnSize,&dwNumConnections))
     {
          return -1;
     }

     // If there are no connections, return zero.
     if (!dwNumConnections)
     {
          return 0;
     }

     // Terminate all of the remote access connections.
     GetConnectionStatus();
    //here add to get selected network
    MySelectNetName=GetMMSSelectNet();
   
    GPRSServerName* P_CMWAPtemp=pCMWAP_backup;
     for (index = 0; index < (int)dwNumConnections; ++index)
     {
         while( P_CMWAPtemp )
         {
              if(!wcscmp(RasConn[index].szEntryName,P_CMWAPtemp->ServerName)||
                !wcscmp(RasConn[index].szEntryName, MySelectNetName))
              {
                   if (dwError = RasHangUp (RasConn[index].hrasconn))
                       
                        RETURN_VALUE=-1;
                   else
                           //successfully disconnect cmwap;
                        RETURN_VALUE=0;
              }
            P_CMWAPtemp = P_CMWAPtemp->pnext ;
          }
     }
    //free mem
     freelink(pCMWAP_backup);
     return RETURN_VALUE;
}