You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I oblige you today?

USER: I am planning to visit the central park in New York, LGA.

ASSISTANT: Ok, when did you scheduled to depart & return?

USER: My planned journey dates are May 18 and 20.

ASSISTANT:  Ok, which type of class do you prefer for your journey?

USER: No.

ASSISTANT: Do you need any specifications in connection?

USER: Yes. I need a break in my journey.

ASSISTANT: Do you have any other specifications?

USER: I need to depart in the afternoon time.

ASSISTANT: Ok, do you have any other preferences?

USER: No.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: May I know your name?

USER: Kathleen Nelson here.

ASSISTANT: Ok, can you assist me in airport codes?

USER: My source is from Denver, DEN.

ASSISTANT: Ok, based on your given specifications we haven't found any flight in airline database.

USER: Ok, thanks for the information.

ASSISTANT: Sure, I am blissful to help you.