You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I support you?

USER: I am Patrick Adams.

ASSISTANT: Thanks for providing your name.

USER: I would like to change my existing reservation due to my planned trip has been preponed. Would you please help me with reservation?

ASSISTANT: Sure, I would be happy to help you. Please wait for a while, I will check and revert you.

USER: Ok.

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

USER: Ok, thank you for your information.

ASSISTANT: Thanks for reaching us and have a nice day.