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

ASSISTANT: Hello, How can I assist you?

USER: As fest is going on in my college so I want to attend the fest, Can you book a ticket for me?

ASSISTANT: Sure. To proceed further I need your travelling dates.

USER: 04/08 to 04/10 with direct flight.

ASSISTANT: Can I know your source and destination airport codes?

USER: Airport codes are from IAD to HOU.

ASSISTANT: Unfortunately, there are no flights available with your requirement.

USER: Ok. Thanks for your information.

ASSISTANT: Thank you for approaching us.