You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: Ruth Martinez here. I want to book a flight ticket from DEN to SFO. Can you help me in that?

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: My trip dates are May 9 to May 11.

ASSISTANT: Do you have any other specifications?

USER: I need a connecting flight and my depart should be in the afternoon.

ASSISTANT: Sorry for this inconvenience, I could not find any flight with your requirements.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us.

USER: Thank you.