You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Gregory Mitchell.

ASSISTANT: How may I assist you today?

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

ASSISTANT: Sure, please wait for some time.

USER: Ok.

ASSISTANT: There is no existing reservation found on your name in our records.

USER: No issue. Thank you.

ASSISTANT: Thank you for availing us.