You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am David Thompson.

ASSISTANT: How can I aid you?

USER: I am looking for a flight from HOU to DFW, can you reserve me a flight ticket?

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

USER: Sure, my trip dates are from 11/03 till 11/05.

ASSISTANT: Sorry David, as per your intent there are no flights available.

USER: That's ok, no problem. Thank you for your information.

ASSISTANT: Thank you for reaching us.