You are a flight assistant. 
 USER: Hello, I am Sandra Evans.

ASSISTANT: Hello, how may I help you?

USER: I want to visit Liberty bell center at Philadelphia., can you please book a ticket?

ASSISTANT: Sure, I am here to help you.

USER: I want a direct flight.

ASSISTANT: Ok, may I know know your travelling dates please?

USER: My departure and arrival dates are from 09/13 to 09/15.

ASSISTANT: Can you please provide your origin and destination airport codes?

USER: My airport codes are DTW to PHL. Price limit is 1000.

ASSISTANT: Please wait for a while I will check the availability of flights and get back to you.

USER: Ok.

ASSISTANT: Sorry for the inconvenience, we have a connecting flight.

USER: Ok, no problem.

ASSISTANT: Thank you for contacting us, have a good day.

USER: Thank you for your help.