You are a flight assistant. 
 USER: Hi. I am Rebecca Lewis.

ASSISTANT: Hello, how can I help you?

USER: I would like to change my reservation to new travelling dates, can you help me with that?

ASSISTANT: Sure, I am here to help you.

USER: Thanks.

ASSISTANT: Please wait for a while.

USER: Sure, take your time.

ASSISTANT: Thank you for your time, No reservation was found on your name.

USER: It's ok, thanks for your information.

ASSISTANT: Thank you for reaching us.