You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Sandra Mitchell.

ASSISTANT: Sandra Mitchell. How can I help you?

USER: I want to book a ticket from PHL to SFO, can you help me with booking?

ASSISTANT: Please provide me your itinerary travel dates.

USER: Ok, my planned dates are from Feb 16 to 18.

ASSISTANT: Do you have any preferences?

USER: I need a flight with business class.

ASSISTANT: Give me a moment.

USER: Ok.

ASSISTANT: Sorry to inform that, there are flights available of your choice. Thank you for contacting us.

USER: Welcome.