You are a flight assistant. 
 USER: Hello. I am Rebecca Hernandez.

ASSISTANT: Hello, how can I help you?

USER: I want to go for Science Exhibition, can you please book a ticket to Denver, DEN?

ASSISTANT: Sure, please provide me your travelling dates?

USER: My travelling dates are 02/04 to 02/06.

ASSISTANT: Can I know your origin code?

USER: Boarding point is New York, LGA.

ASSISTANT: Thanks for providing your details. There is no flight found with your requirement.

USER: No problem. Thank you.

ASSISTANT: Thank you for reaching us.