You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you at this moment?

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

ASSISTANT: Sure, I will help you with that. Can you please mention your preferable travel dates?

USER: My travel dates are May 10 and 12.

ASSISTANT: May I know your name for further process?

USER: My name is Mary Perez.

ASSISTANT: Do you need any specific depart and arrival time for this trip?

USER: I am comfortable with any timings.

ASSISTANT: Do you have any another specifications?

USER: I prefer to travel in economy class.

ASSISTANT: Ok, please hold on a moment.

USER: Ok, make sure I need a connecting flight.

ASSISTANT: Sorry, no flights are available in this route as per your requested dates.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for reaching us.