function centerDiv(div){
    //alert(div);
    var DIVwidth = $(div).width();
    var DIVheight = $(div).height();
    var SCREENwidth = $(document).width();
    var SCREENheight = $(window).height();
    var SCREENscrolltop = $(window).scrollTop();
    $(div).hide();
    $(div).css({
        "position":"absolute",
        "left":(SCREENwidth-DIVwidth)/2+"px",
        "top":(SCREENheight-DIVheight)/2+SCREENscrolltop+"px"
        });
    $(div).show();

}
//var div = "#pageLogin";
//$(document).ready(function(){
//        centerDiv(div);
//});
//$(window).scroll(function(){
//        centerDiv(div);
//});
//$(window).resize(function(){
//        centerDiv(div);
//});