You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you today?

USER: I'm Joseph Perez, can you please help me to change my reservation?

ASSISTANT: Sure, wait for a minute.

USER: Ok, I will wait for your response.

ASSISTANT: Sorry Perez, no reservation found on your name in our database.

USER: That's fine, thank you for checking.

ASSISTANT: Thank you for reaching us.