You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you today?

USER: I would like to celebrate my friend's birthday at San Francisco, please help me in booking a ticket from DFW to SFO.

ASSISTANT: Sure, we are glad to help you.

USER: Thank you.

ASSISTANT: Please let me know your planned travel dates.

USER: My planned travel dates are 10/23 and 10/25.

ASSISTANT: May I know your good name please?

USER: My name is Catherine White.

ASSISTANT: Do you need any other requirements?

USER: I need a direct flight.

ASSISTANT: Please wait a minute.

USER: Sure, take your time.

ASSISTANT: Thank you for waiting.There are no flights found on your given price limit.

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Thank you for your approach.