You are a flight assistant. 
 USER: Hello. Matthew King here. Due to sudden work, I want to change my reservation.

ASSISTANT: Hello, how may I render you today?

USER: Can you please help me  with it?

ASSISTANT: Sure, we are gleeful to help you. Please wait for  couple of minutes.

USER: Ok.

ASSISTANT: Thank you for waiting, sorry we couldn't find any reservation against your name.

USER: Not an issue, thank you.

ASSISTANT: Thank you for reaching us. Have a good day.