function changeBildVergroessern(imgsource, imgid, maxid) {
    document.getElementById('product_picture').src=""+ imgsource +"";
    
    for(var i = 1; i <= maxid; i++) {
        document.getElementById('weitereBilderPic'+ i +'').style.display = "none";
    }
    document.getElementById('weitereBilderMainPic').style.display = "none";
    document.getElementById('weitereBilderPic'+ imgid +'').style.display = "block";
}

function changeBildVergroessernMain(imgsource, maxid) {
    document.getElementById('product_picture').src=""+ imgsource +"";
    
    for(var i = 1; i <= maxid; i++) {
        document.getElementById('weitereBilderPic'+ i +'').style.display = "none";
    }
    document.getElementById('weitereBilderMainPic').style.display = "block";
}