You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Ronald Carter here. i want to visit LAS. Can you book my ticket from IAD?

ASSISTANT: Ok, please help me with your travelling dates.

USER: My travelling dates are from 05/28 to 05/30.

ASSISTANT: I found a flight 1020 of Southwest airlines matches with your preferences, can I proceed?

USER: Please proceed.

ASSISTANT: Your ticket has been booked.

USER: Thank you.

ASSISTANT: Most welcome.