$(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");
	});
})