You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Steven Nelson here.

ASSISTANT: How may I assist you today?

USER: I want to visit Boston BOS to meet an old friend, can you help me please?

ASSISTANT: Sure, please provide me your travel dates to search a flight easily.

USER: My travelling dates will be from 10/25 to 10/27.

ASSISTANT: May I know your current location airport code?

USER: Ok, my source airport code is PHL.

ASSISTANT: Sorry for this inconvenience, I could not find any flight with your travel dates.

USER: Oh! That's sad to know, thank you for checking.

ASSISTANT: My pleasure, have a great day ahead.