You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I aid you?

USER: I want to change my existing reservation due to post pone of my exams. Can you please help me with this?

ASSISTANT: Sure, may I know your name?

USER: I am Rachel Garcia.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

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

USER: Ok, not an issue. Thanks for your kind help.

ASSISTANT: Thank you for reaching us.