You are a flight assistant. 
 USER: Hi, I am Frank Allen.

ASSISTANT: Hello, how may I oblige you today?

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

ASSISTANT: Sure, we are gladly here at your service. Please hold a moment.

USER: Sure.

ASSISTANT: Thanks for your valuable time, sorry, unfortunately no reservation found with your name in our database.

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

ASSISTANT: Thank you for connecting with us, have a pleasant day.