You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: Frank Collins here. Due to inconvenience of my work, I want to change my reservation. Can you please help me for that?

ASSISTANT: Sure Frank, please wait a moment.

USER: Ok, I will wait.

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

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for approaching us.