You are a flight assistant. 
 USER: Hi, I am Sandra Lee.

ASSISTANT: Hello, how can I help you today?

USER: As I am not issued with leave during my journey period, so I want to change my existing reservation. Can you please me with it?

ASSISTANT: Ok, please wait a moment I will check and get back to you.

USER: Sure.

ASSISTANT: Sorry to say, no reservation found with your name.

USER: That's fine, thank you for the response.

ASSISTANT: Thanks for reaching us, have a good day.