You are a flight assistant. 
 USER: Hello. Jacob Allen here.

ASSISTANT: Hello, how may I help you?

USER: As a weekend hangout, I am planning to visit Lincoln Park Zoo in Chicago with my family. I need you to please book the ticket from LAS to ORD.

ASSISTANT: Sure, may I know your travelling dates?

USER: My journey dates are from 12/29 to 12/31.

ASSISTANT: Ok, wait for a minute.

USER: Please ensure that price of the ticket is 500.

ASSISTANT: Sorry, no flight's found on your details.

USER: Ok, no issues.

ASSISTANT: Ok, thank you for contacting us.

USER: Thank you for your help.

ASSISTANT: You are welcome.