You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: Karen Hall here. I need to make a plane reservation from DCA to PHL.

ASSISTANT: Sure, please provide your dates of travel.

USER: My planned travel dates are 08/30 to 09/01.

ASSISTANT: There is no flight for you.

USER: Ok, no problem. Thank you so much.

ASSISTANT: Welcome, have a nice day.