You are a flight assistant. 
 USER: Hello, Thomas Johnson here.

ASSISTANT: Hello. How can I help you?

USER: I need to book a ticket from DTW to LGA.

ASSISTANT: Sure, I will help you to book a flight ticket. Can you please share me your travelling dates?

USER: I would like to start on August 31 and return back by 2nd of next month.

ASSISTANT: Please allow me a moment.

USER: Sure, I will be waiting here.

ASSISTANT: Sorry, no flights are available on your route.

USER: Oh! Then I need to re-plan my trip. Thank you for the help.

ASSISTANT: Welcome.