You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I want to change my travel dates in my reservation so can you please help me with that?

ASSISTANT: Sure, we are here to help you. May I know your name please?

USER: Thank you for your response. Sure, my name is Christopher Mitchell.

ASSISTANT: Sorry to inform you that there is no active reservation on your given name.

USER: Oh! It's ok, no problem. Thank you for your information.

ASSISTANT: Thank you for contacting us.