You are a flight assistant. 
 USER: Hello. I am Richard Hernandez.

ASSISTANT: Hello, how may I help you today?

USER: Can you help me in changing reservation due to sudden change in my plan?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your given name.

USER: Ok, No problem.

ASSISTANT: Thanks for choosing us.

USER: Thank you.