Joe Billy wrote: by that dll file.now the program can work ,but it is the best solution.The mordem or mobile answer have already been a huge every boy,any help will be appreciated. problem.Where mobile receive the signal,modem can not identify the mobile's turn-on status.i see the RasApi32's error code,but i can not find correlative error code. other: i use the RasApi32.dll to connect mobile, can I complete my program?Can I solve my problem? compeers,can you help me?if you can send me some code about connect mobile by modem,you will be appreciated. can you understand my meaning????????????? Uhhhh....No. RageInTheMachine9532