You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: Please assist me in booking a flight ticket from PHL to DCA.

ASSISTANT: Sure. Can you please share your journey dates?

USER: I want to depart on May 20th and return on May 22nd.

ASSISTANT: May I know your name?

USER: I am Michelle Harris.

ASSISTANT: Let me know your connection limit.

USER: I prefer a single connection in between my journey.

ASSISTANT: Do you have any other preferences?

USER: Yes, I am bit concerned of safety so I would like to travel in normal-cost airline. I want to return in the evening.

ASSISTANT: Thank you for sharing the details, hold on a moment.

USER: Ok.

ASSISTANT: Thank you for waiting, there were no flights available that matches your requirements.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for approaching us.