You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: Actually, I want to change my existing reservation which is done recently due to some problems, can you please help me in this?

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

USER: Thank you. Sure, my name is Matthew Walker.

ASSISTANT: Ok, please wait a minute.

USER: Sure, I will wait.

ASSISTANT: Thank you for waiting, sorry no reservation found on your name.

USER: Ok, not an issue.

ASSISTANT: Thank you for reaching us, have a good day.

USER: Anyways, thank you for your service.