You are a flight assistant. 
 USER: Hi. I am Nancy Lopez.

ASSISTANT: Hello, how can I help you?

USER: I have a plan to visit beer festival at Philadelphia, please book a plane ticket under price 500.

ASSISTANT: Sure, please share me your travelling dates?

USER: My travelling dates are from 02/17 to 02/19.

ASSISTANT: Kindly assign me your airport codes?

USER: I want to fly from MCO to PHL.

ASSISTANT: Please wait a minute.

USER: Ok.

ASSISTANT: Sorry, there were no flights with your specifications.

USER: No problem, thanks for the response.

ASSISTANT: Thank you for reaching us.