You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you today?

USER: I am George Brown here. I would like to change my existing reservation, which is done recently. Can you please help me out?

ASSISTANT: Sure, please wait.

USER: Sure, I will wait for your positive response.

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

USER: Not a big problem, thank you for the information.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your service.