You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Myself Linda Mitchell. I want to book a ticket from DCA to LGA.

ASSISTANT: Please mention your travel dates.

USER: My departure is on 12/29 and my arrival is on 12/31.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, there are no flights available matching your requirements.

USER: Ok. Thank you for the help.

ASSISTANT: Thank you for approaching us.