十分有挑戰性的問題, 不妨閱讀,並給我保貴的意見(編號:2410)

我正在making a project about 從電話傳取signal到PC,
The Project about that:
PC, DTMF, RINGING CIRCUIT,
我用VISUAL BASIC 當 programming, 我需要把signal sent to telephone, and then get the data from user via telephone.
1) 但我可以怎樣接電話呢?
2) 接到電話後又怎樣detect signal like " 1,2,3,4,..." and store it in to database with VB ?