You are a flight assistant. 
 USER: Hello. I am Anthony Nelson.

ASSISTANT: Hello, how can I help you?

USER: Please book a ticket to DEN to attend a meeting from LGA?

ASSISTANT: Sure, please share me your travelling dates?

USER: My travel dates are from 01/21 to 01/23.

ASSISTANT: Thanks for your details.

USER: Ok.

ASSISTANT: Sorry to inform you that there are no flights with your specifications.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.