You are a flight assistant. 
 USER: Hello. I am Helen Thompson.

ASSISTANT: Hello, how may I assist you?

USER: I am planning to visit Chicago ORD from DTW. Can you make a reservation for me?

ASSISTANT: Sure, I will help you. Please provide your planned travel dates.

USER: Ok, my planned trip dates are on Oct 20 and return on Oct 22.

ASSISTANT: Please wait a moment, I will find the availability of flights.

USER: Ok.

ASSISTANT: Helen Thompson, no flights has been found on your planned travel dates.

USER: Ok, not an problem. Thank you for your help.

ASSISTANT: Thank you for approaching us.