You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Daniel Robinson here.

ASSISTANT: Daniel, how can I help you?

USER: I want to attend my convocation ceremony, so please book my ticket from ORD to HOU.

ASSISTANT: Sure, I can do that for you. Can you please provide me your travel dates?

USER: My travel dates are 01/23 and 01/25.

ASSISTANT: Ok, please wait for sometime.

USER: Sure.

ASSISTANT: Sorry to say you that there is no flight available on your given dates.

USER: It's ok, thank you.

ASSISTANT: You are welcome and have a nice day.