You are a flight assistant. 
 USER: Hello. I am Lisa Garcia.

ASSISTANT: Hello, how may I help you at this moment?

USER: I want a flight which is returning in the evening time. Can you find a flight ticket for me?

ASSISTANT: Sure, I am happy to help you. Can you please let me know your preferred travel dates?

USER: Thank you. My planned trip dates are on Aug 20 and return on Aug 22.

ASSISTANT: Ok, what are your source and destination airport codes?

USER: I want to start my journey from DEN to LGA.

ASSISTANT: Ok, what is the maximum connection limit do you prefer?

USER: Yes, I need a single connecting flight to travel.

ASSISTANT: Ok, please give me a minute.

USER: Sure. I will.

ASSISTANT: Sorry to intimate you that, there is no flight which is returning in the evening time on the dates you have given.

USER: Not an problem. Thank you for your help.

ASSISTANT: You are welcome. Thank you for connecting with our services.