You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am David Allen.

ASSISTANT: David Allen. How may I help you?

USER:   I am planning to travel  from IAD to LAX, help me in booking a flight?

ASSISTANT: Sure, may I know your itinerary dates.

USER: My travelling dates are 02/18 to 02/20.

ASSISTANT: Please give me a moment.

USER: Ok.

ASSISTANT: Delta airlines with flight 1004 is providing service on your route.

USER: Proceed for booking.

ASSISTANT: Your ticket has been reserved in the economy class with the cost of 100.

USER: Thank you.

ASSISTANT: Thank you for approaching us.