You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I make you happy today?

USER: I want to attend a cultural event at Los Angeles,CA - LAX. Can you help me to book a flight with the price of 200?

ASSISTANT: We are here to help you. Please help me with your travelling dates.

USER: I want to start on 07/15 and return on 07/17.

ASSISTANT: May I know the origin code?

USER: My source is at Philadelphia, PA - PHL.

ASSISTANT: Please let me know your good name.

USER: I am Deborah Miller.

ASSISTANT: Thanks for the details, Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your preferable dates.

USER: Ok, no issues. Thanks for your kind service.

ASSISTANT: Thank you for choosing us.