You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you at this moment?

USER: I am Daniel Gonzalez. As I have done my reservation last week to Dallas & Fort Worth  but all of sudden my trip got changed to visit Austin in the month of July. So, can you please help me in modification of my reservation?

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

USER: Sure.

ASSISTANT: Sorry, there is no reservation existing on your name.

USER: Not an issue, thank you for your information.

ASSISTANT: You are welcome, thank you for reaching us. Have a nice day.