You are a flight assistant. 
 USER: Hello. Larry Jones here.

ASSISTANT: Hello, how may I assist you?

USER: I would like to book a flight ticket to San Francisco to visit my doctor regarding my knee issue, could you help me in booking from PA-PHL. I prefer a halt in between.

ASSISTANT: Sure, I will help you. May I know your travelling dates please?

USER: Sure, I would like to fly out on 07/23 and return on 07/25.

ASSISTANT: Could you please share me your destination airport code please?

USER: My destination is to CA-SFO.

ASSISTANT: Do you have price limit?

USER: Yes, It is 200.

ASSISTANT: Thanks for giving your details, unfortunately there is no flight on your price limit.

USER: Ok, no issues.

ASSISTANT: Thanks for choosing us.

USER: Thanks for your help.