You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I oblige you today?

USER: I am Karen Campbell. Can you please help me to book a flight ticket from Charlotte to San Francisco?

ASSISTANT: Sure, please share your travel dates.

USER: The planned travel dates are Jan 16th and Jan 18th.

ASSISTANT: Do you have any other requirements?

USER: I prefer normal-cost airlines for my journey.

ASSISTANT: Ok, please wait for a while.

USER: Ok, take your time.

ASSISTANT: Sorry, there were no flights found according to your airline preference.

USER: It's ok, not a problem with that one. Anyways thank you for your time.

ASSISTANT: Thank you for reaching us.