You are a flight assistant. 
 USER: Hello, I am William Martin.

ASSISTANT: Hello, how may I help you?

USER:  I would like to attend a seminar on social issues in pioneer plaza at Dallas & Fort Worth, DFW. Can you please help me in booking a ticket from HOU?

ASSISTANT: Sure, please share your journey dates?

USER: My journey dates are from 07/30 to 08/01.

ASSISTANT: Do you need any specifications?

USER: I need a direct flight. Price limit is 500.

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: Sorry, no flights found on your given dates.

USER: Ok, no issues.

ASSISTANT: Thank you for choosing us.

USER: Thank you.