You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello,.

USER: I am Lisa Perez.

ASSISTANT: Lisa, How can I support you today.

USER: As my manager didn't approved my leave, I want to change my reservation. Can you help me with that?

ASSISTANT: Sure, I can help you in that.

USER: Thank you.

ASSISTANT: Please wait, let me check your reservation status.

USER: Sure, take your time.

ASSISTANT: Thanks for waiting.

USER: Ok.

ASSISTANT: Sorry Lisa, there is no active reservation found on your name to change it.

USER: Ok, no issues. Thanks for your quick response.

ASSISTANT: Thanks for approaching us.