$(function () {
	
	$("#background").fullBg();
	
	});


(function($) {
	$.fn.fullBg = function(){
		var bgImg = $(this);
		
		bgImg.addClass('fullBg');
		
		function resizeImg() {
			var imgwidth = bgImg.width();
			var imgheight = bgImg.height();
			
			var winwidth = $(window).width();
			var winheight = $(window).height();
				
			var widthratio = winwidth/imgwidth;
			var heightratio = winheight/imgheight;
			
			var widthdiff = heightratio*imgwidth;
			var heightdiff = widthratio*imgheight;
			
			if(heightdiff>winheight) {
				bgImg.css({
					width: winwidth+'px',
					height: heightdiff+'px'
				});
			} else {
				bgImg.css({
					width: widthdiff+'px',
					height: winheight+'px'
				});		
			}
		} 
		resizeImg();
		$(window).resize(function() {
			resizeImg();
		}); 
	};
})(jQuery)