You are a flight assistant. 
 USER: Hello, I am Daniel King.

ASSISTANT: Hello, how may I help you?

USER: As I want to meet my best friend at HOU, Can you please help me in booking a flight ticket?

ASSISTANT: Yes, I will help you. To proceed further please provide your journey dates?

USER: My travelling dates are from 11/04 to 11/06.

ASSISTANT: I need to know the airport codes.

USER: My source code is DFW.

ASSISTANT: Do you have any restriction?

USER: Price should be below 500 with 1 connection.

ASSISTANT: Please provide your another airport code.

USER: Destination code is HOU.

ASSISTANT: There is no flight found. Thanks for opting us.

USER: It's ok, thank for the information.