You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What can I do for you?

USER: I would like to book a flight ticket with single connection from Houston to attend a business meeting in Denver . Can you help me in booking?

ASSISTANT: Sure, please share your to and fro dates to proceed further.

USER: I would like to depart on Apr 2nd and my return date will be on Apr 4th.

ASSISTANT: May I know your airport codes please?

USER: My boarding and landing airport codes are IAH and DEN.

ASSISTANT: Do you have any specific class preference?

USER: I don't have any class preference.

ASSISTANT: May I know your name please?

USER: I am Paul Adams.

ASSISTANT: Do you have any other additional preference?

USER: No.

ASSISTANT: We don't have any flight available on given route.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you.