You are a flight assistant. 
 USER: Hi, I am Angela Clark.

ASSISTANT: Hello, how may I assist you?

USER: Can you please help me with booking a flight ticket from LAS to IAH?

ASSISTANT: Sure, may I know your planned travel dates please?

USER: Travel dates are 12/11 and 12/13.

ASSISTANT: Sorry, there is no flight available on your requested dates.

USER: No problem, thanks for the information.

ASSISTANT: You are welcome.