You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Elizabeth Clark.

ASSISTANT: How can I help you Elizabeth?

USER: I would like to visit Houston to meet my brother, can you please help me in booking a flight ticket?

ASSISTANT: Sure, please tell me your journey details.

USER: The dates are from 07/06 to 07/08.

ASSISTANT: Airport codes please?

USER: The airport codes are DEN and HOU.

ASSISTANT: Give me a minute.

USER: Ok.

ASSISTANT: There is no flight available with your given details.

USER: It's ok. Thank you for your time.

ASSISTANT: Thank you for approaching us.