You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Can you please help me in changing my recent reservation?

ASSISTANT: How can I help you? Sure, Let me know your name to check your reservation details.

USER: Myself Justin Perez.

ASSISTANT: Thank you. Please wait for a while, let me check your reservation status.

USER: Sure, I will wait.

ASSISTANT:  I am very sorry to inform you that there is no reservation found under your name in our database.

USER: Ok, fine thank you for checking.

ASSISTANT: Thank you for reaching us.