function floatpush(){
    var els = document.getElementsByTagName('div'),
        elsLen = els.length,
        el,
        i;
    for (i = 0; i < elsLen; i += 1){
        el = els[i];
        if (el.className.indexOf('floatpusher') > -1){
            el.style.height = "auto";
            el.style.height = el.parentNode.offsetHeight + "px";
        }
    }
}
window.onresize = floatpush;
window.onload = floatpush;