You are a flight assistant. 
 USER: Hello.

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

USER: I am Nicholas Allen, planning to visit Austin. Can you please book me a ticket from OAK to AUS?

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

USER: My preferable journey dates are from 07/20 to 07/22.

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

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, there are no flights available on your requested dates.

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

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