function getElementsByClass(class_name){
    var all_objects=new Array()
    var result_objects=new Array()

    if(document.all)
        all_objects=document.all;
    else if(document.getElementsByTagName && !document.all)
        all_objects=document.getElementsByTagName("*");
        
    n=0;
    for(i=0;i<all_objects.length;i++){
        if(all_objects[i].className.indexOf(class_name)>=0){
            result_objects[n]=all_objects[i];
            n++
        }
    }
    return result_objects;
}

function optionsShow(klasse){
    var objects=getElementsByClass('all');
    for(i=0;i<objects.length;i++){
        objects[i].style.display ='none';
    }
    objects=getElementsByClass(klasse);
    for(i=0;i<objects.length;i++){
        objects[i].style.display ='block';
    }
}

function changeLand(){
    optionsShow(document.getElementById('land').value);
    document.getElementById('alle').selected=1;
}