You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I serve you now?

USER:  Will you please assist me to change my existing reservation as my plan to meet my friend got postponed?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Please share me on which name your reservation was done?

USER: Anna Phillips here.

ASSISTANT: Thank you for your name, sorry Anna Phillips there is no reservation found against your name in our system data to change it.

USER: No issue, Thank you for the information.

ASSISTANT: Thank you for visiting us, we hope see you again.