You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I serve you today?

USER: I want to change my existing reservation which is done recently due to some problems, can you please help me in this?

ASSISTANT: Sure, I will help you with that. May I know your good name?

USER: Sure, my name is Elizabeth Rodriguez.

ASSISTANT: Please wait for a moment, while I check for your reservation.

USER: Sure, I will wait.

ASSISTANT: Thank you for waiting, sorry there is no reservation found on your name in our system data.

USER: Ok, no problem. Anyways, thank you for your service.

ASSISTANT: Thank you for visiting us, we hope see you again.