You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I am Jason Smith want to visit Houston, can you book a ticket on 07/24 and 07/26?

ASSISTANT: May I know your desired airport code please?

USER: Yes, I want to fly from PHL to HOU.

ASSISTANT: There is no flight on your desired travel dates.

USER: That's ok, thank you.

ASSISTANT: Thank you for opting us.