You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I provide assistance today?

USER: I am planing to give a surprise visit to my dad on his birthday, help me to find a flight.

ASSISTANT: Sure, can you provide me your travelling details?

USER: I need a flight on 04/06 and return flight on 04/08.

ASSISTANT: Ok, can you provide me airport codes?

USER: My destination location is Houston, TX-HOU and my origin airport is Phoenix, AZ-PHX.

ASSISTANT: Ok, wait for a while and I will check and revert you back.

USER: Ok.

ASSISTANT: Please let me know your name?

USER: Stephen Rodriguez.

ASSISTANT: Thank you for your time, we could not find any flight that matches your specifications.

USER: Thanks for the information.

ASSISTANT: Thanks for choosing us.