You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. Can you please tell me how can I assist you?

USER: I want to change my reservation, can you help me?

ASSISTANT: Can you please let me know your name to search for your reservation status?

USER: Myself Sandra Perez.

ASSISTANT: Sorry, I did not fine any reservation on your name to change.

USER: No problem, thanks for checking.

ASSISTANT: Thank you for reaching us.