You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I best support you?

USER: I am Linda Martin, I would like to change my existing reservation, so can you help me for that?

ASSISTANT: Sure, please wait a while.

USER: Ok, I will wait for your reply.

ASSISTANT: Thanks for waiting. There was no reservation found on your name.

USER: Oh! It's ok, no problem.

ASSISTANT: Thank you for consulting us.

USER: Thank you for your services.

ASSISTANT: Have a great day.