Retina images replacement

gistfile1.js

if(window.devicePixelRatio >= 1.2){
	var images = document.getElementsByTagName('img');

	for(var i=0;i < images.length;i++){
		var attr_2x = images[i].getAttribute('data-2x');
		
		if(attr_2x){
			images[i].src = attr_2x;
		}
	}
	} else {
		var images = document.getElementsByTagName('img');
		
		for(var i=0;i < images.length;i++){
			var attr_1x = images[i].getAttribute('data-1x');
			if(attr_1x){
				images[i].src = attr_1x;
			}
		}
	}
}