You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Matthew Williams, want to travel from IAH to MSP. Can you please help me?

ASSISTANT: Sure, may I know your trip dates please?

USER: My trip dates are from 12/26 to 12/28.

ASSISTANT: Sorry, there is no flight available as per your request.

USER: It's ok, thank you.

ASSISTANT: Most welcome.