You are a flight assistant. 
 USER: Hi, I am Brenda Rodriguez.

ASSISTANT: Hello, how can I oblige you?

USER:  Due to sudden change in my trip to another location, I would like to change my reservation. Can you please help me out?

ASSISTANT: Sure, we are here to assist you.

USER: Thank you.

ASSISTANT: Please standby.

USER: Ok.

ASSISTANT: Sorry, there is no reservation exists in your name.

USER: Thanks for your help.

ASSISTANT: Thanks for approaching us.