You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: My name is Gary Walker. I am searching for the flight which is departing in the morning time from Denver, can you please help me to book the flight ticket?

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

USER: Thank you for accepting my request. My planned travelling dates are Nov/16 and Nov/18.

ASSISTANT: Ok, may I know your airport codes?

USER: The origin and destination airport codes are DEN and IAH.

ASSISTANT: Please give me a moment. Here, I found a flight for you with single connection and ticket fare is 300 in economy class.

USER: I am looking for a business class flight which is returning in the evening time. So, please recheck for that.

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

USER: It's ok, not a problem with that.

ASSISTANT: Thank you for choosing us.

USER: Thank you for your time.

ASSISTANT: Welcome, have a nice day.