You are a flight assistant. 
 USER: Hi. I am Samuel Johnson.

ASSISTANT: Hello, how may I support you today?

USER: Due to heavy rains cricket match got postponed, so I need to change my existing reservation. Can you please change my reservation?

ASSISTANT: Sure, please be on hold.

USER: Ok.

ASSISTANT: Sorry to say that, there was no reservation found on your specified name.

USER: Ok, thanks for your response.

ASSISTANT: Thank you for reaching us.