You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello. How can I serve you?

USER: I am Mark Jones, I want to book a flight ticket to go for a round trip with in the range of 500. Can you assist me in booking a flight ticket?

ASSISTANT: Sure, I can help you. Can I know your travelling dates?

USER: Sure, 07/03 and 07/05 are my travelling dates.

ASSISTANT: May I know your preferable airport codes?

USER: My airport code is Orlando, FL - MCO.

ASSISTANT: Do you have any connection limit?

USER: Yes, I need a halt.

ASSISTANT: May I know your another airport code?

USER: It is a round trip, I already mentioned above please check it once.

ASSISTANT: OK. Please wait a while.

USER: Ok.

ASSISTANT: Thanks for being waiting. Unfortunately, there are no flights found according to your requirements.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for contating us.