Added a seatManager Method to manage Set selection for taken seat, will alow user to browse seat only if its not taken,
then updates set taken status and update seat display for unavailable seat icon when user presses Purchaise button

added pop-up window to tell user to enter name before seat selection

added pop-up window to show user that seat is taken if that seat is un-available

added playsound function for playing audio clips
added isSeatTaken(int seatIndex) to check if seat is taken
   
added  takeSeat to set seat taken status
added seat taken icon for first class seat
added audio clip for expreiment..will need to find more clips.