You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I would like to do my project work at Houston, please help me in booking a ticket from DEN to HOU.

ASSISTANT: Sure, may I know your planned travel dates please?

USER: My planned travel dates are 05/21 and 05/23.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, there is no flight available on your requested dates.

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

ASSISTANT: May I know your good name please?

USER: My name is Edward Lopez.

ASSISTANT: Thank you.