You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am William Thompson.

ASSISTANT: Do you need any help from my side?

USER: Can you help me in changing my recent reservation?

ASSISTANT: Sure, I will try my best and please be on hold for a while to check it.

USER: Sure.

ASSISTANT: Thank you for being on hold, I have checked with your information in my portal to change your booking but is displayed that there is no user name found to change it.

USER: Its ok, thank you.

ASSISTANT: You are most welcome and have a great day.