function schaalFoto(el) {
    var el2 = document.getElementById(el);
    var publicInhoudHoogte = document.getElementById('links').offsetHeight;
    if (el2 != undefined) {
        document.getElementById('linkstekst').style.height = Math.max((publicInhoudHoogte - el2.offsetHeight -20),0) + 'px';
    }
}