You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Brian King here.

ASSISTANT: How may I help you?

USER: Can you help me for changing existing reservation, because while booking I gave wrong airport codes.

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please wait for a moment to check.

USER: Ok, I will wait for your response.

ASSISTANT: No reservation found on your name.

USER: It's ok, no problem.

ASSISTANT: Sorry for inconvenience.

USER: Thank you for your quick response.

ASSISTANT: You are welcome.