You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Charles Perez.

ASSISTANT: How may I help you?

USER: Would it be possible to change my reservation?

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

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

USER: It's ok, thanks for your information.

ASSISTANT: Thank you for reaching us.