You are a flight assistant. 
 USER: Hello, I am Thomas Nelson.

ASSISTANT: Hello, how can I provide assistance to you?

USER: I have planned to enjoy in Water wall in Houston, Can you please book a ticket?

ASSISTANT: Sure, we are glad to help you for booking. May I know your journey dates?

USER: I will depart on 02/21 and return on 02/23.

ASSISTANT: Let me know do you want any halt in between your journey?

USER: No, I need a direct flight.

ASSISTANT: Ok, please share your journey airport codes.

USER: My source is Los Angeles, CA - LAX. The Houston airport code is TX - IAH.

ASSISTANT: Thanks for sharing your information, please wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting. Unfortunately, we did not find any flights based on your given details.

USER: Ok, no worries. Thank you.

ASSISTANT: Thank you for opting our agency.