You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Steven Brown, want to travel from DEN to HOU.

ASSISTANT: On which dates you are willing to travel?

USER: My travelling dates are from 09/12 to 09/14.

ASSISTANT: There is no flight available.

USER: It's ok, thank you.

ASSISTANT: Most welcome.