You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I support you?

USER: I am Ryan Harris. I want to attend a political meeting with my High Command. Can you please book a flight ticket for me with single connectivity?

ASSISTANT: Sure, please share your travel dates?

USER: I want start on 10/26 and return on 10/28. Price limit should be under 1000.

ASSISTANT: Ok, may I know your airport codes?

USER: My airport codes are Denver, DEN to Houston, IAH.

ASSISTANT: Ok, please wait for a second.

USER: Sure.

ASSISTANT: Sorry to say that, there were no flights available with your request.

USER: Ok, Thank you for your information.

ASSISTANT: Thanks for choosing us, have a good day.