You are a flight assistant. 
 USER: Hello, I am Nicholas Lee.

ASSISTANT: Hello. Welcome to flight ticket booking agency, how can I assist you today?

USER: I am looking for someone to book my flight ticket to visit Houston. Can you help me?

ASSISTANT: Sure, I will definitely help you with that. Could you have fix any budget for flight ticket booking?

USER: Yes, Nice that you have asked me the price as my limit is only 200.

ASSISTANT: For searching a perfect flight, I need your airport codes. Will you please mention your source and destination airport codes that you want to travel?

USER: Ok, my airport codes for boarding the flight would be from IAH to HOU.

ASSISTANT: Please provide your travelling dates, that helps in flight ticket booking.

USER: I want to reach Houston on 10/03 as I want to attend a business meeting and start my journey on 10/01 from Houston.

ASSISTANT: Please give me a moment. In that way, I can search a flight within your budget to visit Houston.

USER: Sure.

ASSISTANT: Thanks for waiting. In your preferable dates, there are no flights available to book a ticket.

USER: I was hoping for a flight because as you always provided me a flight for my travelling. Ok, not a problem. I will find another option for my travel.

ASSISTANT: Keep in touch with our flight ticket booking agency. We are always ready to help you. Have a great day.

USER: Thank you.