Hello.
Hello, how may I aid you?
 Actually, I want to meet my friend in New York for that I reserved my ticket before one month back, but suddenly I had a another work at that time. So can you help me to change my reservation?
Sure, I will help you with the change of flight reservation. May I know your name please?
Previously I reserved with the name of John Smith.
I regret to inform you that, there is no reservation on your name. Thanks for approaching us.