function switchRuby (show) {
		if(!document.styleSheets) return;
		window.onerror = function() { return true; }

			var sheet = document.styleSheets[
			document.styleSheets.length - 1];
			if(sheet.insertRule) {
				if(sheet.cssRules.length == 0) {
				sheet.insertRule("rp { display: none; }", 0);
				sheet.insertRule("rt { display: none; }", 1);
				}

			else {
				sheet.deleteRule(1);
				sheet.deleteRule(0);
			}
		}

		else if(sheet.addRule) {
			if(sheet.rules.length == 0) {
			sheet.addRule("rp", "display: none;", 0);
			sheet.addRule("rt", "display: none;", 1);
			}

		else {
			sheet.removeRule(1);
			sheet.removeRule(0);
			}
		}
	}