Adds class to the html tag in order to address any styling quirks specific to those brosers. Example class might be "IE IE-9" or "iOS iO7-iPad".

Detect Browser

// Detect IE and iOS and add browser class to document
var tag = document.getElementsByTagName('html')[0];
var ua = navigator.userAgent;
var version = '';
if (/msie (\d+)/i.test(ua)) {
	version = 'IE IE-' + /msie (\d+)/i.exec(ua)[1];
	if (tag.className.length > 0) {
		tag.className = tag.className + ' ' + version;
	} else {
		tag.className = version;
	}
} else if (/trident.*?; rv:(\d+)/i.test(ua)) {
	version = 'IE IE-' + /trident.*?; rv:(\d+)/i.exec(ua)[1];
	if (tag.className.length > 0) {
		tag.className = tag.className + ' ' + version;
	} else {
		tag.className = version;
	}
} else if (/\((\w+).*?OS (\d).*?like Mac OS X/i.test(ua)) {
	version = 'iOS iOS' + /\((\w+).*?OS (\d).*?like Mac OS X/i.exec(ua)[2] + '-' + /\((\w+).*?OS (\d).*?like Mac OS X/i.exec(ua)[1];
	if (tag.className.length > 0) {
		tag.className = tag.className + ' ' + version;
	} else {
		tag.className = version;
	}
}