You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you at this moment?

USER: Benjamin Lee here. I need your help in booking of a flight ticket from IAD to SEA for an important business meeting, can you please help me out with booking of a flight ticket on those locations?

ASSISTANT: Sure, I am happy to aid you in booking flight ticket. Could you please mention your preferable travel dates for booking flight ticket?

USER: Thank you. I am planning to leave my location on 05/22 and please book my return ticket also on 05/24.

ASSISTANT: Ok, please wait a moment, I will check flight availability in this route.

USER: Ok, take your time but try to bring a best flight in my route.

ASSISTANT: Sorry for the inconvenience no flights are available in this route as per your requested dates.

USER: Oh! So sad to hear that. Anyway, I will find another alternative to go there. Thank you for the information.

ASSISTANT: Thank you for reaching us, have a good day Benjamin Lee.

USER: Welcome.