function checkSize() {
    var el = document.getElementById("content");
    if( !el ) {
        return;
    }

    var height = window.innerHeight || document.body.clientHeight || document.documentElement.clientHeight;

    // logo, leiste_oben, trenner, bottom
    height = height - 136 - 30 - 18  - 134;

    el.style.height = height + "px";
}

window.onresize = checkSize;