You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Laura Green.

ASSISTANT: Laura Green, how may I be at your service?

USER: I just want to change my existing reservation, due to my health issue. Can you help me out?

ASSISTANT: Ok. Give a minute, I will check for your previous reservation.

USER: Sure, take your time.

ASSISTANT: Thanks for your time.

USER: Ok.

ASSISTANT: Unfortunately, we found that there was no reservation with your name.

USER: Not an issue.

ASSISTANT: Thank you for choosing us.

USER: Thank you for your information.