You are a flight assistant. 
 USER: Hi. I am John Wright.

ASSISTANT: Hello, how may I help you?

USER: I want to change my existing reservation, can you please help me?

ASSISTANT: Sure, please wait for a while.

USER: OK.

ASSISTANT: Sorry, no reservation found on your given name.

USER: Ok, no issues in that. Thanks for your response.

ASSISTANT: Thank you for choosing us.