You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How can I help you?

USER: I am Lisa Perez want to book a flight ticket from Philadelphia to Phoenix, so can you book me a direct flight?

ASSISTANT: Sure. May I know your travelling dates?

USER: Yes, my travelling dates are 03/15 and 0. Return date is 03/17.

ASSISTANT: Can you share your airport codes?

USER: Yes, my airport codes are PA-PHL and AZ-PHX.

ASSISTANT: Do you have any price limit?

USER: Yes, my price of ticket should be under 5000.

ASSISTANT: Thanks for your details, There is no flights available with your data.

USER: That's ok, thank you for the response.

ASSISTANT: Thanks for choosing us.