I'm writing a C# program that uses TAPI to make a telephone call.
1 - Call a specified number. [OK]
2 - Wait for answer or busy signal. [PROBLEM]
3 - Play a wav file. [OK]
4 - Hang up.
The problem is in step 2. It can't detect whether someone answered the phone or the line was busy.
Please see attach project.
Only need fix that BUG!!