You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Donna Hernandez.

ASSISTANT: How may I address you today?

USER: I want to change my reservation as my get together program got postponed. Can you help me?

ASSISTANT: sure, please wait a moment.

USER: Ok.

ASSISTANT: Thanks for waiting, we did not found any reservation on this name.

USER: It's Ok thanks for your assistance.

ASSISTANT: Thanks for approaching us.