You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: Gregory Brown here. I would like to visit Houston to meet my school friend, please help me in booking a ticket from DEN to IAH.

ASSISTANT: Ok, may I know the travel dates?

USER: My travel dates are 04/02 and 04/04.

ASSISTANT: Ok, please wait for a while.

USER: Sure, take your time.

ASSISTANT: Sorry Brown, I did not find any flight available on your given travel dates.

USER: Ok, no issues. Thank you for your information.

ASSISTANT: You are welcome and thank you for choosing us.