You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: I am  Stephen Adams. I want to change an existing reservation due to sudden change in my trip. Can you help me with this change reservation?

ASSISTANT: Sure, I will help you. Please, wait a minute.

USER: Ok.

ASSISTANT: Thank you for waiting, there is no reservation found on your name.

USER: No issue, I will choose an other alternative. Thank you for the information.

ASSISTANT: Thank you for approaching us.