//by bpxqz@126.com
jQuery.tab_nav = function(options) {
    var defaults = {
        list:"",
        links:"",
        old_img:"",
        new_img:"",
        ipath:"images/"
    }
    var setting = jQuery.extend({},defaults,options);
    for(var i in setting) {
        if(setting[i]=="" || setting[i]==null ) {
                alert("参数配置错误");
                return false;
        }
    }
    var list = setting["list"];
    var links = setting["links"];
    var old_img = setting["old_img"];
    var new_img = setting["new_img"];
    var ipath = setting["ipath"];
    var csty = setting["csty"];

    preload(ipath,old_img);
    preload(ipath,new_img);

    function preload(imgpath,imgarr) {
        var alength=imgarr.length;
        for(var i=0;i<alength;i++) {
            var pimg = new Image();
             pimg.src=imgpath+imgarr[i];
        }
    }

    jQuery(document).ready(function(){
    jQuery.each(list,function(i,n){ //初始化
		if(i==0) {
			jQuery(n).css("display","block");
		}
		else {
		    jQuery(n).css("display","none");
		}
	});

	function closenac() { //关闭所有
		jQuery.each(list,function(i,n){
			jQuery(n).css("display","none");
		});
		jQuery.each(links,function(i,n){
			jQuery(n).children("img").attr("src",ipath+old_img[i]);
		});
	};

	jQuery.each(links,function(i,n){ //切换效果
		jQuery(n).click(function() {
			closenac();
			jQuery(list[i]).fadeIn("slow");
			jQuery(this).children("img").attr("src",ipath+new_img[i]);
            jQuery(this).blur();
		})
	});
});
}