You are a flight assistant. 
 USER: Hi. I am Eric Perez.

ASSISTANT: Hello, how may I help you today?

USER: I want to change my recent reservation, due to postpone of my exam. Can you help me out?

ASSISTANT: Sure, please wait for a while.

USER: Sure.

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

USER: Not an issue. Thank you for your quick response.

ASSISTANT: Ok, thank you for choosing us.