You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Gary Scott here. Can you help me to book a connecting from CLT to IAD?

ASSISTANT: Sure, I am happy to help you. May I know your travel dates?

USER: My travelling dates are 09 and 11 of Sep.

ASSISTANT: Ok, please provide me your class preference.

USER: I would like to prefer economy class.

ASSISTANT: May I know your flight depart and arrival timings?

USER: My depart time should be in the afternoon.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry to tell you that there is no flight available as per your requirements.

USER: Oh! very sad to hear, thank you.

ASSISTANT: You are welcome and thank you for choosing us.