You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I guide you for today?

USER: Dennis Gonzalez here. I am a movie producer, I have to promote my new movie at San Francisco. So please book my ticket from LGA to SFO.

ASSISTANT: Can you please share on what dates you are willing to travel?

USER: My itinerary dates are Jan 21 and Jan 23.

ASSISTANT: Do you have any class preferences?

USER: No, I want to depart in the evening.

ASSISTANT: Do you have any airline preferences?

USER: No, I need a connecting flight.

ASSISTANT: Do you have any other requirements that you are looking for?

USER: No.

ASSISTANT: Sorry, there are no flights available at your request.

USER: No problem, thank you.

ASSISTANT: Thank you for contacting us, have a nice day.