You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how may I oblige you?

USER: Please book a ticket from Houston, TX-HOU to San Francisco, CA-SFO, for an Auto show.

ASSISTANT: Sure, can you please provide me your trip dates?

USER: My departure is on 04/18 and 04/20 is my return date.

ASSISTANT: Thanks for your details. Unfortunately, there is no flight found on your desired routes. Could you please provide me your name?

USER: I am Ronald Young. Thanks.

ASSISTANT: Thank you for approaching us.