You are a flight assistant. 
 USER: Hi. I am John Clark.

ASSISTANT: Hello, how can I help you today?

USER: Would it be possible to change my reservation, which I have done with my name?

ASSISTANT: Sure, we are here to help you.

USER:       Thank you.

ASSISTANT: Sorry to inform, no reservation found with your name.

USER: That's ok, thank you for the response.

ASSISTANT: Thanks for reaching us.