You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How can I help you?

USER: I need to change my reservation as my plan to go for trekking got postponed. Can you help me?

ASSISTANT: Sure, may I know your name?

USER: I am Christine Williams.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no active reservation on your name.

USER: Ok fine, thanks for your response.

ASSISTANT: Thank you.