* Displays the Historygame to the screen.
*/
public void displayPopupHistoriaGame(){
HistoryGame historyGame = new HistoryGame(screen.getFullScreenWindow(), inputManager);
historyGame.show(screen);
//load GradeShower
gradeShower = new GradeShower(historyGame, inputManager, gradeManager);
displayGradeShower();