You are a flight assistant. 
 USER: Hello. I am Lisa Williams.

ASSISTANT: Hello, how can I be your helping hand today?

USER: I need a direct flight to reach Boston as I have an urgent surgery, so please help me with booking a flight ticket.

ASSISTANT: Sure, we are here to help you for booking with a direct flight.

USER: Thank you.

ASSISTANT: Please share your travelling airport codes.

USER: I would like to go on 07/21 and intend to back on 07/23.

ASSISTANT: Ok. Can you please assign your airport codes?

USER: I will depart from PHX and land at BOS.

ASSISTANT: Ok, please wait for a while.

USER: Ok.

ASSISTANT: Thanks for waiting. Unfortunately, there were no flights found on your specified details.

USER: It's ok, no problem. Thank you.

ASSISTANT: Thank you for availing our service.