You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Thomas Lopez here.

ASSISTANT: How may I guide you today?

USER: Please help me out in changing my recent reservation due to some personal problem.

ASSISTANT: Sure, I will help you with that.

USER: Ok.

ASSISTANT: Please wait for a minute.

USER: Ok.

ASSISTANT: I am sorry to say that there is no reservation found under your name.

USER: That's ok, thank you for informing.

ASSISTANT: Thank you for reaching us.