You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you at this moment?

USER: I am John Johnson.

ASSISTANT: Nice to meet you John.

USER: I need to attend a conference meeting at Chicago ORD. Can you help me with booking from Washington DCA?

ASSISTANT: Sure, I will try to book a flight ticket from DCA, can you share your travelling dates?

USER: I will fly on 04/16 and arrival on 04/18.

ASSISTANT: Wait for a minute.

USER: Sure.

ASSISTANT: Sorry, I could not find any flight with your travelling dates.

USER: Ok, no worries at all. Thank you for your information.

ASSISTANT: My pleasure.