You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Virginia Allen.

ASSISTANT: How may I help you, Allen?

USER: Heard that Colorado Springs in Denver is the best place to enjoy the weekends, please book me a ticket from CLT to DEN.

ASSISTANT: Sounds good. I'm glad to help you. May I know your journey dates please?

USER: My journey dates are from 03/28 to 03/30.

ASSISTANT: There are no flights available with your preferences, Allen.

USER: Ok, no problem, I'll find any other source of travel.

ASSISTANT: Thank you for contacting us.

USER: Thank you for your information.