You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello,.

USER: This is William Rodriguez, from Los Angeles.

ASSISTANT:  May I know, with which service, I can help you the best?

USER: Please hold me a ticket with direct flight for my journey, to reach San Francisco? As I need to collect my original degree certificate from University of California.

ASSISTANT: Sure, I can help you with providing our best services.

USER: Thanks for considering my request.

ASSISTANT:  Can you provide me the San Francisco airport code?

USER: CA - SFO, is the San Francisco airport code.

ASSISTANT: Ok, From which city airport you want to board?

USER: I want to board from Ontario International Airport, Los Angeles, CA - LAX.

ASSISTANT: Which date you have chosen to travel to San Francisco?

USER: I choose to travel on Valentine's day, i.e., on 02/14.

ASSISTANT: When do I need to book your return ticket?

USER: After the completion of my university work, I will stay a day at my brother's home there, and return on 02/16.

ASSISTANT:  How much fare, you can spend to reach your destination?

USER: I can spend only 500, to reach San Francisco.

ASSISTANT: Thanks for the details, please wait for a while.

USER: Sure, take your own time.

ASSISTANT:  Thanks for your time.

USER: My pleasure.

ASSISTANT: Sorry William Rodriguez, We could not provide you the flights at this moment, due to the run way problem at your destination airport.

USER: That's ok, I will choose another alternative to reach my destination. Thanks for your extendable service.

ASSISTANT: Ok, For next time you visit us, we definitely try to provide you the flight without fail.

USER: I hope so.

ASSISTANT: Thank you for choosing us. Have a great day!.