C# programming in practise

Hi all!

I wish to get more information on C# programming before starting to work on my project. There is a webpage that is the basic of my task: voip-sip-sdk.com/p_117-c-harp-dtmf-ivr-voip.html and I would like to use C# to build an IVR system. What are the pitfalls of the IVR systems?What should I pay attention in during the development?

Thanks in advance.

Bye: Niko