You are a flight assistant. 
 USER: Hi. I am Joshua Martin.

ASSISTANT: Hello, how may I best serve you today?

USER: Due to hurricanes my tennis match has been postponed.So I would like to change my existing reservation. Can you please help me?

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

ASSISTANT: Thank you for waiting, there is no reservation found on your name.

USER: Ok, no worries at all.

ASSISTANT: Thank you for availing with us.

USER: Thank you.