You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Lisa Mitchell here.

ASSISTANT: How may I assist you today?

USER: I am planning to book a flight ticket to IAD from MCO, can you please help me out?

ASSISTANT: Sure, may I know your travelling dates?

USER: I would like to travel on 04/23 and return on 04/25.

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

USER: It's ok, no problem. Thank you.

ASSISTANT: My pleasure.