You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how can I address you today?

USER:  I want go to Houston, TX-IAH on Oct 12th to give a surprise to my parents to celebrate their 25th wedding anniversary.

ASSISTANT: To proceed further, May I know some more details of your journey?

USER: I prefer to start on 10/12 from Los Angeles CA-LAX and want to return on 10/14.

ASSISTANT: Thank you for the details, May I know your good name?

USER: I am Andrew Lee by the way.

ASSISTANT: Please wait a moment, I will check the availability of flights and get you back.

USER: OK,.

ASSISTANT: Thank you for waiting, Unfortunately we found no flights matching your requirements.

USER: Thank you for your information.

ASSISTANT: Thank you for reaching us, Have a nice day ahead.