private void hold() {
		if (holdUsed) {
			// TODO: Alert the user they can't switch again with perhaps a sound
			return;
		}
		
		game.fallTimer.stop();
		
		if (holdBlock != null) {
			Block temp = gameBlock;
			
			gameBlock = holdBlock;
			holdBlock = temp;
			
			gameBlock.freeGrid();
			holdBlock.insert(holdGrid);
			if (!insertBlock(gameBlock)) {
				gameOver(false);
				return;
			}
		}
		else {
			holdBlock = gameBlock;
			holdBlock.insert(holdGrid);
			
			if (!getNext()) {
				gameOver(false);
				return;
			}
		}
		
		holdUsed = true;
		fallTimer.start();
	}