You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am Jessica Anderson. I like to travel from IAH to SFO, can you help in booking?

ASSISTANT: Ok. Can I know the dates of travel?

USER: My date of travel is 12/13 to 12/15. I want direct flight.

ASSISTANT: I'm sorry, there are no flights matching your preferences.

USER: That's ok. Thank you for your help.

ASSISTANT: Thank you, have a good day.