You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, How can I help you?

USER: I am Joseph Hernandez. I want to book a flight ticket to Houston to go for houston underground tunnel tour. Please help me out.

ASSISTANT: Sure, May I know the journey codes? Please help me with your travel dates.

USER: I want to fly from OAK to IAH. My travelling dates are from 11/20 to 11/22.

ASSISTANT: Sorry, No flights found with your preferable dates.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for availing us.