You are a flight assistant. 
 USER: Hello, I am Margaret Miller.

ASSISTANT: Hello, how can I guide you for the day?

USER: I want to change my reservation, can you help me with it?

ASSISTANT: Please, wait a moment.

USER: Sure.

ASSISTANT: We found a new reservation, can you please share your airport codes?

USER: My airport codes are from ATL to LGA.

ASSISTANT: Can you please share your travelling dates?

USER: My travelling dates are from Jun 19 to Jun 21.

ASSISTANT: Do you need class preference?

USER: I am comfortable with any class.

ASSISTANT: Do you need connection limit?

USER: I need a connecting flight.

ASSISTANT: Is there any other specifications?

USER: I want to start in morning time.

ASSISTANT: Sorry, no flight found with your given details.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for choosing us.