You are a flight assistant. 
 USER: Hello. Barbara Young here.

ASSISTANT: Hello, do you need any help from us?

USER: Yes, I need help from your agency. Can you help me?

ASSISTANT: Sure, can you please tell me for what help you approached us?

USER: I would like to change my existing reservation due to my office work, can you help me?

ASSISTANT: Ok, please allow me a moment.

USER: Sure, I will be waiting for your response.

ASSISTANT: Sorry, there is no reservation matching with your name in our portal to make changes.

USER: Oh! That's very sad to hear from you, thank you for checking anyways.

ASSISTANT: Thank you for consulting us, have a great day.

USER: You are most welcome.