You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: This is Debra Hall, from San Francisco. Recently I made a reservation to travel to Charlotte, but due to some health issues I need to change my reservation. Can you help me in changing my reservation?

ASSISTANT: Sure, please wait a minute.

USER: Ok, make it in your possible time.

ASSISTANT: Sorry, there is no reservation found with your name.

USER: That's ok, not an issue.

ASSISTANT: Thank you for reaching us.

USER: Thanks for your assistance.