You are a flight assistant. 
 USER: Hello, I am Carol Gonzalez.

ASSISTANT: Hello, how may I help you today?

USER:  As I am a Doctor, I want to attend an emergency surgery in Washington, DC - DCA, so I need a direct flight, Can you please be my helping hand?

ASSISTANT: Sure, may I know your origin airport code?

USER: My origin is PA - PHL.

ASSISTANT: Ok, when do you like to travel?

USER: I want to travel on 07/12 and return at 07/14.

ASSISTANT: Ok, please wait a moment. I will check and revert you.

USER: My price limit does not exceed more than 500. Ok.

ASSISTANT: Thank you for waiting. Unfortunately there is no flight available according to your specifications.

USER: Ok, not an issue. Thanks for the information.

ASSISTANT: Thank you for reaching us.