You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may 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, let me know your name please.

USER: I am Eric Scott.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, we regret to inform you that there is no active reservation found with your name in our records.

USER: That's Ok, thanks for your response.

ASSISTANT: Most welcome.