导航条下面的横线随鼠标移动（对应的栏目）

 

 

 

$(document).ready(function(){
    var $liCur = $(".nav ul li.cur"),
      curP = $liCur.position().left,
      curW = $liCur.outerWidth(true),
      $slider = $(".curBg"),
      $navBox = $(".nav");
     $targetEle = $(".nav ul li a"),
    $slider.animate({
      "left":curP,
      "width":curW
    });
    $targetEle.mouseenter(function () {
      var $_parent = $(this).parent(),
        _width = $_parent.outerWidth(true),
        posL = $_parent.position().left;
      $slider.stop(true, true).animate({
        "left":posL,
        "width":_width
      }, "fast");
    });
    $navBox.mouseleave(function (cur, wid) {
      cur = curP;
      wid = curW;
      $slider.stop(true, true).animate({
        "left":cur,
        "width":wid
      }, "fast");
    });
})