You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I am David Thompson. I would like to change my recent reservation, can you help me to change this reservation?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Wait for some time I will check and get back to you.

USER: Sure, take your own time.

ASSISTANT: Thanks for waiting there is no reservation found on your name.

USER: That's fine, thanks for your information.

ASSISTANT: Thanks for approaching us.