You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you for the day?

USER: I am Elizabeth Green. I am planning to travel on these days that is on Mar 21 and return on Mar 23. Can you make a reservation for me?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Can you help me with your airport codes?

USER: Ok, my planned airport codes are from EWR to CLT.

ASSISTANT: Do you have any class preference?

USER: Yes, I want to return in the evening.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, we found no fights on your given dates.

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

ASSISTANT: Thank you for reaching us.