You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you today?

USER: Can you change my existing reservation which I have done with my name Rachel Edwards.

ASSISTANT: Sure, wait for a minute.

USER: Sure, take your time.

ASSISTANT: Thanks for your time, we hardly tried to find your reservation but, no reservation has been found with your name.

USER: It's ok, not an issue. Anyway thanks for checking.

ASSISTANT: Thanks for choosing us, hope to serve you again.