You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Betty Evans here.

ASSISTANT: Evans, how may I assist you today?

USER: Can you please help me to change my reservation?

ASSISTANT: Sure, I will help you in changing, please hold on for a moment to check your reservation status.

USER: Sure, I will wait for your reply.

ASSISTANT: I found your reservation, can you share your airport codes?

USER: My airport code are DFW and ORD.

ASSISTANT: May I know your travelling dates?

USER: My trip dates are from 08/04 to 08/06.

ASSISTANT: Sorry, no flights as per your details. Thank you for reaching us.

USER: Ok, no problem. Welcome.