You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I am Helen Young. Houston Zoo is one of famous Zoo in the country, so I am planning a trip there. Can you book a ticket for me?

ASSISTANT: That's nice. I can help you with that.

USER: Thanks.

ASSISTANT: Could you share me your airport codes?

USER: My airport codes are IAH and HOU.

ASSISTANT: Ok, can I know your travelling dates?

USER: It's from 11/30 to 12/02.

ASSISTANT: Give me a moment.

USER: Sure.

ASSISTANT: I have found a flight ticket with a price of 700 and a connection 1. Can I proceed?

USER: Can you check with the price 500.

ASSISTANT: Sorry, there is no flight ticket with a price of 500 or below. Sorry for the inconvenience provided.

USER: It's fine. Anyway, thank you for your help.

ASSISTANT: You are welcome.