You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Andrew Lewis here.

ASSISTANT: How may I aid you at this moment?

USER: Actually, I am looking for a flight having single connection because my friend also booked the same flight that I want to travel, so can you please help me out with booking of a flight ticket from Charlotte on 08/19?

ASSISTANT: Sure, I will help you with that. May I know your airfield locations?

USER: Thank you. I want to travel from CLT to IAD.

ASSISTANT: Ok, can I know your return date?

USER: I would like to return on 08/21.

ASSISTANT: Sorry to say that, there are no flight's found based on your travelling dates.

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

ASSISTANT: Thank you for approaching us.

USER: Welcome.