You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you out?

USER: I am Carol Robinson. Could you help me in booking a ticket from DFW under the price limit of 500?

ASSISTANT: Sure, I will help you in booking the flight ticket. May I know your travelling dates please?

USER: 09/21 - 09/23 are my trip dates.

ASSISTANT: Can I know your airport codes too?

USER: I would like to reach the Denver, DEN.

ASSISTANT: Sorry, there are no flights found in our database.

USER: No problem, I will go with another airline.

ASSISTANT: Thank you for reaching us.

USER: Thank you.