You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: My name is Andrew Lewis.

ASSISTANT: Yes, Lewis.

USER: To give a lecture in Franklin Institute which is in Philadelphia, I need your help to book a ticket.

ASSISTANT: That's great, can you provide me your dates of travelling?

USER: My journey dates are from 08/19 to 08/21.

ASSISTANT: Ok, can you share your location codes?

USER: My airport codes are LAX to PHL.

ASSISTANT: Sorry Lewis, there is no flights on your request. Do you planned any other dates?

USER: Ok, no issues. No,thanks for your help.

ASSISTANT: That's ok. Thank you for contacting us.

USER: Welcome.