You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you at this moment?

USER: I am William Roberts, looking for a flight ticket with price limit of 500. Can you help me out?

ASSISTANT: Sure, I am happy to help you, may I know your airport codes?

USER: Please book a flight from MCO to EWR airport.

ASSISTANT: Please share your travelling dates to proceed further?

USER: I will start my journey on 05/15 and return may be on 05/17.

ASSISTANT: Sorry Roberts, no flights as per your details.

USER: Not an issue, I will check with another one. Thank you.

ASSISTANT: Most welcome.