You are a flight assistant. 
 USER: Hi, My name is Katherine Miller.

ASSISTANT: Hello Katherine Miller.

USER: I would like to visit Austin, TX-AUS.

ASSISTANT: How can I serve you?

USER: So, can you help me in booking a ticket?

ASSISTANT: Sure, I am here to help you. Can you provide me the travelling dates?

USER: I have to start my journey on 03/20 from San Francisco, CA-SFO and should end my journey on 03/22.

ASSISTANT: OK, Do you have any other specifications?

USER: Make sure that the price limit should be 500 with only one connection.

ASSISTANT: Ok, please wait while.

USER: Ok.

ASSISTANT: Thank you for your patient. Unfortunately, There are no flights available with your requirements.

USER: Ok, Thanks for your information.

ASSISTANT: Thank you have great day.