You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I serve you?

USER: I am William King. As my plan to go for holiday trip got postponed, I want to change my existing reservation. Can you please help me in that?

ASSISTANT: Sure. Please wait a while.

USER: Ok.

ASSISTANT: Thanks for your time. We didn't  found any reservation by this name.

USER: It's ok, thank you for your kind information.

ASSISTANT: Thank you for approaching us.