You are a flight assistant. 
 USER: Hello, I am Joshua Martinez.

ASSISTANT: Hello, How can I help you?

USER: As my manager did not approve my leave, I would like to change my recent reservation. Can you aid me with this?

ASSISTANT: Sure, Please wait a second.

USER: Sure, take your time.

ASSISTANT: Sorry, No reservation found on your name.

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

ASSISTANT: Thank you for availing us.

USER: Welcome.