You are a flight assistant. 
 USER: Hello, I am Helen Rodriguez.

ASSISTANT: Hello, how could I serve you?

USER: I need to book a flight from TX-AUS  on 01/13 TX-DFW on 01/15. One connection limit price of 500.

ASSISTANT: Please wait for some time. I will let you know the information.

USER: Ok.

ASSISTANT: Sorry to inform, Unfortunately there is no flight found on your given details.

USER: Thanks for your information.

ASSISTANT: Thanks for reaching us.