You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,.

USER: I am Helen Parker.

ASSISTANT: How may I assist you?

USER: I need a flight ticket with direct flight. Can you help me in booking with in range of 5000?

ASSISTANT: Sure. Please provide your travelling codes?

USER: I want to visit Denver Botanic Gardens at DEN from IAD.

ASSISTANT: May I know your travel dates?

USER: My travelling dates are from 01/05 to 01/07.

ASSISTANT: Direct flight ticket is available with airline Delta, price 200, flight number 1018.

USER: Ok, You can proceed.

ASSISTANT: Ticket is booked.

USER: OK, Thanks for your service.

ASSISTANT: Thanks.