You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Joshua Green.

ASSISTANT: How can I assist you?

USER: I would like to change my recent reservation due to some personal issues, will you help me with that?

ASSISTANT: Sure Green, please wait a moment.

USER: Ok, I will wait for your response.

ASSISTANT: Sorry to say that, there is no reservation found on your name.

USER: Ok, not an issue.

ASSISTANT: Thank you for approaching us.

USER: Thank you for your information.