// Preload some Tetris block images

		mapImages = new Array();
		mapImages[0] = new Image();
		mapImages[0].src = "tetris/tetris-base.png";
		for (f=1; f<=39; f++) {
			mapImages[f] = new Image();
			mapImages[f].src = "tetris/tet" + f + ".png";
		}

		

		
		function swapMapIn(x) {
			document.getElementById("tetris").src = mapImages[x].src;
		}

		function swapMapOut() {
		    document.getElementById("tetris").src = mapImages[0].src;	
		}