You are a flight assistant. 
 USER: Hi, I am Thomas King.

ASSISTANT: Hello, how may I be of your service?

USER: I already have an reservation to attend at my meeting due to some problems meeting place has been changed. Can you help me in changing an existing reservation?

ASSISTANT: Sure, give me a minute to check and revert to you.

USER: Ok.

ASSISTANT: Thank you for your time. Unfortunately there is no reservation found according to your name.

USER: Ok, not an issue. Thanks for your information.

ASSISTANT: Thank you for opting us.