You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I guide you for today?

USER: Donna Turner here. I want to book a flight ticket for my journey from Austin AUS to SFO, can you help me?

ASSISTANT: Can you please share on what dates you are willing to travel?

USER: My journey will be starting on 07/18, and I would like to return on 07/20.

ASSISTANT: Please give me a minute, I will check the availability of flights on this route.

USER: Ok, take your time to check with availability.

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

USER: Oh! No issues with it, thank you for checking anyways.

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

USER: Welcome.