You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I address you?

USER: Can you aid me change my reservation that I have done recently?

ASSISTANT: Sure, may I know your name please?

USER: Mark Martinez here.

ASSISTANT: By your name there is no active reservation found.

USER: Oh! it's Ok. Thank you for the help.

ASSISTANT: Thank you for choosing our agency.