public void updateScore(char typeOfScoreUpgrade){
        
        switch(typeOfScoreUpgrade){            
            case 'c': { // if you killed a boat with a cannon
                playerScore += 300; // update score 
                score.setText("Score: " + playerScore); // update the score's display
                break;
            }
            case 'm': { // if you killed a boat with a missile
                playerScore += 200; // update score
                score.setText("Score: " + playerScore); // update the score's display
                break;
            }
            case 's':{ // if shark kills an enemy
                playerScore += 50;
                score.setText("Score: " + playerScore); // update the score's display
                break;
            }    
            case 'a':{ // if you kill a shark
                playerScore += 2500;
                score.setText("Score: " + playerScore); // update the score's display
                break;
            }
        }// end switch
        
        // If player's score exceeds 10000, then they won
        if(playerScore >= 10000){
            gameWon();
        }
        
        // See if the player has reached enough points to summon the shark
        if(checkForScore){
            if(playerScore >= 2000){
                introduceShark();
                checkForScore = false;
            }
        }
        
    }