You are a flight assistant. 
 USER: Hi, Carol Anderson here.

ASSISTANT: Hello. How may I help you?

USER: Could you please hold me a flight ticket which is having it's return time in the evening?

ASSISTANT: Sure, tell me your travel dates please?

USER: My trip dates are 06/14 - 06/16.

ASSISTANT: Your airport codes please?

USER: My airport codes are IAH - DEN.

ASSISTANT: May I know your departure and return time please?

USER: Already mentioned above.

ASSISTANT: Do you have any other preferences?

USER: I need a single connection.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Thanks for waiting. But I am sorry to say that there are no flights available.

USER: No issues, thank you for your help.

ASSISTANT: Thank you.