$(window).width();
$(document).width();
$(window).height();
$(document).height();

$(function(){
    $(window).resize(function(){
        var h = $(window).height();
        var w = $(window).width();
        $("#elementToResize").css('height',(h < 1024 || w < 768) ? 500 : 400);
    });
});

jQuery.event.add(window, "load", resizeFrame);
jQuery.event.add(window, "resize", resizeFrame);

function resizeFrame()
{
    var h = $(window).height();
    var w = $(window).width();
    $("#elementToResize").css('height',(h < 1024 || w < 768) ? 500 : 400);
}