var lf = {
	
	version: 1.0,
		
	preload_images: function(image_urls) {
		var p = new Image();
		image_urls.each(function(url) {
			p.src = url;
		});
	},
	
	correct_ie_pngs: function() {
		var rslt = navigator.appVersion.match(/MSIE (\d+\.\d+)/, '');
		var itsAllGood = (rslt != null && Number(rslt[1]) >= 5.5);
		for (var i = document.images.length - 1, img = null; (img = document.images[i]); i--) {
			if (itsAllGood && img.src.match(/\.png$/i) != null) {
				var src = img.src;
				var div = document.createElement("DIV");
				div.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='" + src + "', sizing='scale')"
				div.style.width = img.width + "px";
				div.style.height = img.height + "px";
				img.replaceNode(div);
			}
			img.style.visibility = "visible";
		}
	},
	
	stripe_table: function(table_id) {
		if(typeof table_id != 'object' && typeof table_id != 'undefined') {
			if(table_id.substr(0,1) != ".") {
				table_id = "#"+table_id;
			}
		} else {
			table_id = ".stripe_table";
		}
		
		$$(table_id +' tbody tr:nth-child(even)').each(function(item) {
			item.addClassName('even');
		});
	}
}

lf.user_agent = {
	is_web_kit: function() {
		return /Konqueror|Safari|KHTML/.test( navigator.userAgent );
	},
	
	is_ie: function() {
		return /MSIE/.test( navigator.userAgent );
	},
	
	is_opera: function() {
		return /Opera/.test( navigator.userAgent );
	},
	
	is_ff: function() {
		return /Firefox/.test( navigator.userAgent );
	}
}