You are a flight assistant. 
 USER: Hello. I am Sandra Williams.

ASSISTANT: Hello, how may I aid you today?

USER: As I am a doctor, I need to attend an emergency case in Phoenix, but unfortunately I have selected my destination code as Dallas. Can you help me to change my reservation with correct destination code as Phoenix?

ASSISTANT: Sure, we are here to help you. Please wait a moment.

USER: Sure.

ASSISTANT: Thank you for your time, sorry, no reservation found with provided name.

USER: Ok, thank you for informing me.

ASSISTANT: Thank you for opting us.