function startRotateBlocks(){	
try{
rotateBlocksScriptEnabled=true;
if (document.getElementById && document.createTextNode){
		var rotationGroups = getElementsByClass('rotation-group');
	
		for (var i=0; i<rotationGroups.length; i++) {
			var rotationBlocks = getElementsByClass('rotation-block', rotationGroups[i]);
			for (var j=0; j<rotationBlocks.length; j++) {
				rotationBlocks[j].className = rotationBlocks[j].className.replace('show-rotation-block', '');
				rotationBlocks[j].className = rotationBlocks[j].className.replace('show-block', '');
			
			}
			var randomIndex = Math.floor(Math.random() * rotationBlocks.length);
			rotationBlocks[randomIndex].className +=' show-block';
			
		}
}
}catch (err){ }
}