You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you?

USER: Please help me to book a flight ticket from HOU to DEN.

ASSISTANT: May I know your itinerary dates?

USER: My journey dates are from June, 01 to June, 03.

ASSISTANT: May I know your name?

USER: Katherine Lewis.

ASSISTANT: Sorry Katherine Lewis, no flights are available on your planned dates.

USER: Thank you for your information.

ASSISTANT: Thank you for reaching us.