You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I am Mark Lee, I want to book a flight ticket to LGA from DEN in the month of May.

ASSISTANT: Sure, may I know your planned dates of travelling to go there?

USER: Sure, my dates of trip are 05/26 an d05/28.

ASSISTANT: Please wait a moment to check the flights.

USER: Ok, sure.

ASSISTANT: Sorry to inform you that, there are no flights available to your region with your planned dates of travelling.

USER: It's ok, anyway thank you for the help.

ASSISTANT: Thank you for reaching us, have a great day.