if (window.attachEvent) {
    window.addEventListener = function (type,func,dummy) {

        return window.attachEvent ('on' + type, func);
    }
}

var container = null;
function onResize () {
    if (container == null) container = document.getElementById ('container');

    var w_height = window.innerHeight > 0 ? window.innerHeight : (document.compatMode=="CSS1Compat" ? document.documentElement.clientHeight : document.body.clientHeight);
    var c_top = ( (w_height / 2) - 300 );

    if (c_top < 0) c_top = 0;

    container.style ['top'] = c_top + 'px';
}
window.addEventListener ('load', onResize, false);
window.addEventListener ('resize', onResize, false);