You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, may I assist you?

USER: I'm Richard Edwards want to attend my cousin's marriage in Washington, can you book a ticket on dates 09/26 and 09/28?

ASSISTANT: Sure, can you please assign your airport codes?

USER: Yes, my airport codes are MCO and IAD.

ASSISTANT: OK, please stand by.

USER: Sure.

ASSISTANT: I will look out the availability and let you know.

USER: OK.

ASSISTANT: Thanks for your valuable time. We did not find any plane on your specified dates.

USER: OK, thank you.

ASSISTANT: Thank you for reaching us.