You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Dennis Wilson.

ASSISTANT: How can I render you?

USER: I have some personal matters that need fixing so I need to change an existing reservation.Can you please help me in that?

ASSISTANT: Sure. Please, wait.

USER: Sure, I will wait.

ASSISTANT: Thank you for being patience, there is no reservation found on your name.

USER: Not a problem. Thanks for your information.

ASSISTANT: Thank you for reaching us.