You are a flight assistant. 
 USER: Hi. I am Elizabeth Brown.

ASSISTANT: Hello, how may I aid you today from my end?

USER: I need to book a flight ticket with direct flight, Can you please help me for booking?

ASSISTANT: Sure, I am here to help you out. Please provide me your trip dates.

USER: I would like to travel on 06/03 to return on 06/05.

ASSISTANT: May I know the location airport codes?

USER: My source point is PHL to DCA.

ASSISTANT: Do you have any requirement?

USER: I don't need any requirement.

ASSISTANT: Sorry Elizabeth Brown, there is no flight as per your travel dates.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for reaching us.