You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: I need a to attend for training session in Denver, can you please make a reservation from DFW to DEN?

ASSISTANT: Ok, I am here to help you with that. Can I know your planned trip dates?

USER: My journey dates are on Apr 29th and intend to return back on May 1st.

ASSISTANT: Ok, do you have any other requirements?

USER: Yes, I need a flight with single connection. And my depart time should be in the evening.

ASSISTANT: May I know your good name?

USER: My name is Ashley Lopez.

ASSISTANT: Ok, wait for a minute.

USER: Sure.

ASSISTANT: Sorry to say that, there are no flights available based on your travelling dates.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for approaching us.