You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How may I help you today?

USER: I am Donna Perez. I want to change my existing reservation due to my football match got postponed, can you please help me with that?

ASSISTANT: Please give me a moment, let me check your reservation and revert to you.

USER: Sure.

ASSISTANT: We are sorry to inform you that we did not find any reservation on your given name,.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for choosing us.