You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I want to change my recent reservation, can you please help me in that?

ASSISTANT: Sure, may I know your name please?

USER: My name is Patrick Garcia.

ASSISTANT: I am sorry no reservation  found on your name.

USER: Ok, that's not a problem. Thanks for your information.

ASSISTANT: Thank you for choosing us.