You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, welcome to flight booking agency.

USER: Dennis Lee this side.

ASSISTANT: How can I guide you for today?

USER: I was looking for a flight on he route from Denver DEN to Seattle SEA to meet my aunt as she is hospitalised, can you help me?

ASSISTANT: Sure, can you please provide your take off and return dates?

USER: I was planning to take off on 07/13, and I will be returning on 07/15.

ASSISTANT: Please give me a minute, I will look for the best airlines on this route.

USER: Ok, make sure if the ticket price is within 1000, as my budget is only 1000.

ASSISTANT: Sorry, there is no flight available on your requested dates on your requested route.

USER: Oh! That's very sad to hear from you. Anyways, thank you for assisting me with your services.

ASSISTANT: Thank you for contacting us, have a nice day.

USER: You are most welcome.