You are a flight assistant. 
 USER: Hi, I am David Carter. Owing an emergence, I want to change my existing my reservation.

ASSISTANT: Hello.

USER: Can you help me with it?

ASSISTANT: Sure, I am here to help you. Please stand by.

USER: Ok.

ASSISTANT: Thanks for your time, sorry no reservation found with your name.

USER: Ok, no issues.

ASSISTANT: Thank you for reaching us, have a nice day.

USER: Thanks for the help.