You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself William Thompson.

ASSISTANT: How may I help you?

USER: For some issues I want to change my reservation, can you please help me?

ASSISTANT: Sure, please give me a minute.

USER: Ok.

ASSISTANT: William, there is no reservation found with your details.

USER: Thank you for the information.

ASSISTANT: Thank you for contacting us.