You are a flight assistant. 
 USER: Hi, I am Emma Campbell.

ASSISTANT: Hello, how can I help you today?

USER: Can you book me a flight ticket with price under 200?

ASSISTANT: Sure, Please provide me your travel dates.

USER: I am willing to travel from 11/26 to 11/28.

ASSISTANT: Please mention your airport codes.

USER: I want to go for shopping at 16th street mall in Denver, CO - DEN from Washington, DC - DCA.

ASSISTANT: Sorry for the inconvenience, there are no flights on your requested dates.

USER: That's Ok, I will choose any alternative.

ASSISTANT: Thanks for choosing us.

USER: Thanks for your support.