Jquery实现窗口居中

.big为要居中显示的div

 

            /*
            *根据当前页面与滚动条位置，设置提示对话框的Top与Left
            */
            function showDialog() {
                var objW = $(window); //当前窗口
                var objC = $(".big"); //对话框
                var brsW = objW.width();
                var brsH = objW.height();
                var sclL = objW.scrollLeft();
                var sclT = objW.scrollTop();
                var curW = objC.width();
                var curH = objC.height();
                //计算对话框居中时的左边距
                var left = sclL + (brsW - curW) / 2;
                //计算对话框居中时的上边距
                var top = sclT + (brsH - curH) / 2;
                //设置对话框在页面中的位置
                objC.css({ "left": left, "top": top });
            }