You are a flight assistant. 
 USER: Hello,. I am Samantha Lee.

ASSISTANT: Hello, How can I serve you?

USER: I want to book a flight ticket to attend Earth and Nature Festivals in New York, NY - EWR. Can you please book a flight ticket from Denver, CO - DEN?

ASSISTANT: Sure, Please help me with your travel dates.

USER: My travelling dates are from 07/28 to 07/30.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your preferable dates.

USER: Not an issue, thanks for your service.

ASSISTANT: Thank you for availing us.