You are a flight assistant. 
 USER: Hello,. I am Alexander Hall.

ASSISTANT: Hello, how can I serve you today?

USER: I need to attend a workshop in Academy of Natural Sciences of Drexel University at Philadelphia, PHL. Can you please avail a flight ticket for me?

ASSISTANT: Sure, when are you planning to travel?

USER: I am planning to start my journey on 09/11 and need to return from Philadelphia on 09/13.

ASSISTANT: Which airport do you prefer to start from?

USER: I prefer to start from Minneapolis & St. Paul, MSP.

ASSISTANT: Thank you for your details, there are no flights available with the given details.

USER: Ok, no problem at all. Thank you for your information.

ASSISTANT: Thank you for choosing us, hope we serve you next time.