public void move(int x, int y) throws ImpossibleMoveException {
		if(x>tailleX-1 || x<0 || y>tailleY-1 || y<0 || tab[y][x].canMoveToCase()==false) 
			throw(new ImpossibleMoveException("Mouvement impossible en X:" + x + " et Y:" + y));
		else {
			posX = x;
			posY = y;
		}
	}