You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I render you.

USER: Actually, I had done my reservation previously to travel Chicago this month. But, in my office, they are not assigning any leave on those days. So, I want to change my reservation. Can you help me with that?

ASSISTANT: Sure, may I know your name?

USER: Sure, I am Eric Lee.

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

USER: No problem, thank you for your information.

ASSISTANT: Thank you for choosing us.