鼠标滑过切换图片路径

//切换图片路径
var newImage = new Image(); //预载入图片
var oldImage = $('.img').attr('src');
newImage.src = 'static/images/z_peo_change.png';
$('.b').hover(function(){ //鼠标滑过图片切换
        $('.img').attr('src',newImage.src);
    },
    function(){
        $('.img').attr('src',oldImage);
    });