You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. Is there any help that you are looking from us?

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

ASSISTANT: Sure, I will help you and can you please mention your name while you have used in your previous reservation?

USER: Sure, my name is Samuel Parker.

ASSISTANT: Please allow me a moment to check it.

USER: Sure, I will wait.

ASSISTANT: Thank you for waiting, I have checked based on your request but it is showing that there is no reservation found for the user name in our back end.

USER: Ok, not an issue. Thank you for your service.

ASSISTANT: It's my pleasure to help you and thank you for consulting our agency.