JQuery插件第三十五个：在指定范围内水平垂直居中浮动层

//常量：浮动层的生成时的初始位置坐标,数据来自操作台的坐标与窗口坐标的距离var DIV_X_DIFFERENCE = 194;var DIV_Y_DIFFERENCE = 167;//设置层的坐标(function($) {    $.fn.point = function(options) {        var defaults = { X: 0, Y: 0 };         //坐标对象        var opts = $.extend(defaults, options);        //主要执行过程        return this.each(function() {            $(this).css({ "left": parseInt(opts.X), "top": parseInt(opts.Y) });        });    };})(jQuery);//让当前层水平垂直居中(function($) {    $.fn.positionCenter = function(options) {        var defaults = { box: null };          //操作台box        var opts = $.extend(defaults, options);        if (opts.box == null) return;        var w = $(this).width();        var h = $(this).height();        var marginLeft = parseInt(w / 2);        var marginTop = parseInt(h / 2);        var winWidth = parseInt(opts.box.width() / 2);        var winHeight = parseInt(opts.box.height() / 2);        var left = winWidth - marginLeft;        var top = winHeight - marginTop;        var cp = { X: left + DIV_X_DIFFERENCE, Y: top + DIV_Y_DIFFERENCE };        //主要执行过程        $(this).point(cp);    };})(jQuery);