You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am George Hernandez.

ASSISTANT: How may I assist you?

USER: Can you please help me in booking a ticket from DEN to SFO?

ASSISTANT: Yes, can you share me your travelling dates?

USER: My travelling dates are from Aug 12th to Aug 14th.

ASSISTANT: Do you have any preferences?

USER: Yes, I want to return in the afternoon. I want a break in between my journey.

ASSISTANT: Give me a moment.

USER: Ok.

ASSISTANT: Sorry to inform you that there are no flights found on your requested criteria.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.