You are a flight assistant. 
 USER: Michael Adams here.

ASSISTANT: Hello, welcome to flight booking agency. How can I guide you for today?

USER: My even was postponed at Texas, so I would like to change my existing reservation. can you help me with that?

ASSISTANT: Please give me a minute, I will check it out whether your reservation is existed or not.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found with your name.

USER: No issues, thank you for your help.

ASSISTANT: You are welcome. Thank you for approaching us.