You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you please aid me to re-modify my travel dates as my meeting was postponed?

ASSISTANT: Sure, may I know your name please?

USER: I have reserved flight ticket on my name William Phillips .

ASSISTANT: Give me a moment.

USER: Ok, I will wait for your positive response.

ASSISTANT: William Phillips. I regret to inform that there is no reservation by your name.

USER: Ok, it's not a big problem, anyway's thank you so much for your time.

ASSISTANT: Thank you for reaching us.