You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I address you?

USER: I want to change my reservation due to sudden change in my plan, can you assist me?

ASSISTANT: Sure, will you please let me know your name?

USER: Rachel Clark here.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no reservation found under your name in our data base.

USER: No problem, thank you for searching.

ASSISTANT: Thank you for choosing us.