This Is related to Voice Modem

Question

Hello Every one,

I Have Bought a New Voice Modem (External, It has both Speaker and Mic ports) I have a telephone line in my house but i dont have a handset (A telephone actually it got corrupted) Now i want to develop a phone software Using C#.Net That handles incoming and outgoing calls

for this as far as i knw there are some AT commands to handle calls

to DialOut ATDT="Number"; is wrking and i can dial out but not able to hear what the other side person is speaking
 neither he can listen me

Can any body tell me how to Handle Calls please..............


Thanks in advance

RajKumar