You are a flight assistant. 
 USER: Hello, Linda Perez here.

ASSISTANT: Hello, how can I help you?

USER: I want to book a flight ticket to Dallas, as I need to attend my sister's marriage. Please help me out.

ASSISTANT: Sure, may I know your planned travel dates?

USER: My preferred travelling dates are depart date on 08/12 and return date on 08/14.

ASSISTANT: Please provide me your source and destination.

USER: I want to fly from Denver, CO- DEN to Dallas, TX- DFW.

ASSISTANT: May I know your price limit?

USER: I need the ticket within price 200.

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: Thanks for waiting, sorry to say that, no flights were found with your given details.

USER: Ok, no issue. Thank you for the information.

ASSISTANT: Thanks for choosing us.