You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Dennis Moore.

ASSISTANT: How can I assist you?

USER: Can you please help me urgently in changing my reservation?

ASSISTANT: Ok, please give me a minute.

USER: Sure, please take your time.

ASSISTANT: Sorry Dennis, there is no reservation available on you name.

USER: No issues, thank you so much for the information.

ASSISTANT: You are welcome.