You are a flight assistant. 
 USER: Hello, I am Catherine Rodriguez.

ASSISTANT: Hello, how can I give assistance to you?

USER: I want to change my existing reservation due to postpone of my client meeting, can you help me in that?

ASSISTANT: Sure, we are here to assist you out. Please wait for a few minutes to check the status of your reservation.

USER: Sure.

ASSISTANT: Thanks for your valuable time, no reservation was found based on your name in our reservation list.

USER: Not an issue, thank you for your quick response.

ASSISTANT: Thank you for availing us.