You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: I am Timothy Roberts. Due to heavy rains cricket match got postponed, so I need to change my existing reservation. Can you please help me out?

ASSISTANT: Sure, please wait a minute.

USER: Ok.

ASSISTANT: Thank you for waiting. Unfortunately there is no reservation found according to your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for opting us.