You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I am Brain Gonzalez. I want to book a direct flight ticket to attend an emergency case. Can you help me?

ASSISTANT: Sure, I will help you to book a flight ticket. Can you please share me your travelling dates?

USER: Thank you. 09/19 and 09/21 are my travelling dates.

ASSISTANT: Ok, may I know your travelling airport codes?

USER: LGA and DCA are my airport codes.

ASSISTANT: Ok, please let me know your arrival and departure time?

USER: I need to return in the morning.

ASSISTANT: Sorry, no flights are available on your route.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Welcome, have a nice day.