You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Larry Wright from Seattle.

ASSISTANT: How can I assist you at this moment?

USER: I want to change my travel dates in my previous reservation, due to some problems I am unable to travel those dates so can you please help me with that?

ASSISTANT: Sure, I will help you with this.

USER: Thank you.

ASSISTANT: Larry Wright, there is no active reservation found under your name in our database.

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

ASSISTANT: Thank you for utilising our service.