You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you please book a connecting flight from DEN to SFO?

ASSISTANT: Sure, I am here to help you for this. Could you please share me your trip dates?

USER: Sure, I want to travel on Nov 7 and need to return on Nov 9.

ASSISTANT: Do you have any other criteria regarding your journey?

USER: Yes, I prefer an normal-cost airline.

ASSISTANT: Is there any other specifications?

USER: No.

ASSISTANT: May I know your name please?

USER: My name is Carolyn Davis.

ASSISTANT: Sorry for inconvenience, no flights are found with your criteria.

USER: Ok, not an issue.

ASSISTANT: Thank you very much for approaching our agency.

USER: Thank you for checking.

ASSISTANT: You are welcome.