You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I am Stephanie Thomas here, I would like to visit Philadelphia, can you please help me to book a ticket from BOS to PHL?

ASSISTANT: Sure, may I know your journey dates please?

USER: Ok, my dates of journey is from 12/07 to 12/09.

ASSISTANT: Please give me a minute.

USER: Sure, but make sure that the price limit is 200.

ASSISTANT: There are no flights available at this moment, Thomas.

USER: Ok, no problem. Thank you for your service.

ASSISTANT: Thank you for contacting us.