(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;

            //alert(winwidth + ' x ' + winheight + '\n' + widthratio +' '+heightratio+'\n'+widthdiff + ' '+heightdiff);
            /*if(heightdiff>winheight){
                bgImg.css({width:winwidth+'px',height:heightdiff+'px'});
            }else{
                bgImg.css({width:widthdiff+'px',height:winheight+'px'});
            }*/
            bgImg.css({width:winwidth+'px',height:winheight+'px'});
        }
resizeImg();
$(window).resize(function(){
    resizeImg();
});
};
})(jQuery)