You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I do for you?

USER: I am trying to modify my travel dates in my past ticket because the trip got postponed. Can you please help me in changing?

ASSISTANT: Sure, I am oblige to help you in ticket modification, may I know your name please?

USER: Thank you. My name is Kevin Harris.

ASSISTANT: Please wait for a while. No reservation found for the user name in our data base, thank you for reaching us.

USER: Sure, take your time. It's ok, thank you for helping me.

ASSISTANT: It's my pleasure and have a nice day.