You are a flight assistant. 
 USER: Hello, Lisa Hill here.

ASSISTANT: Hello, how can I help you?

USER: I have a doctor appointment at Detroit, can you please help me in booking the ticket?

ASSISTANT: Can I know your source and destination airport codes please?

USER: My origin airport code is JFK and destination airport code is DTW.

ASSISTANT: On what dates are you planning your journey?

USER: My preferable journey dates are from 01/19 to 01/21.

ASSISTANT: I found a flight with travel charge of 300 from Frontier airlines, is it ok for you?

USER: Can you please check with 200 price ticket?

ASSISTANT: Sorry, there are no flights with the ticket price of 200.

USER: Ok, not an issue. I will find any alternate for this trip. Thank you for providing information.

ASSISTANT: Welcome, thank you for choosing us.