You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you help me to change the reservation I had done recently?

ASSISTANT: Sure, I can help you. May I know your name?

USER: My name is Jack Miller.

ASSISTANT: Thank you. Please wait, let me check your reservation status.

USER: Ok, please take your own time.

ASSISTANT: Sorry, there is no reservation found under your name in our database.

USER: Ok, thank you for assisting me. May be my brother had change it for me.

ASSISTANT: You are welcome and have a nice day.