You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Sharon Wright.

ASSISTANT: How may I assist you today?

USER: I would like to book a ticket from DCA to EWR, can you please help me out?

ASSISTANT: May I know on which dates you are willing to travel?

USER: I am travelling on these dates 04/25 and 04/27.

ASSISTANT: Wait for a minute.

USER: Sure.

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

USER: Ok no problem, thank you for your services.

ASSISTANT: Thanks for choosing us.