function overlay(startDiv,id,offset){
	var obj = document.getElementById(startDiv);
	var box = document.getElementById(id);
	var overlay_ShadeFF = document.getElementById('overlay_ShadeFF');
	if (box){
		var offsetTop = obj.offsetTop-offset;
		clone = box.cloneNode(true);
		obj.parentNode.appendChild(clone);
		clone.style.display = 'block';
		clone.style.top = offsetTop+ 'px';
		box.parentNode.removeChild(box); //verwijder het origineel
		overlay_ShadeFF.style.display = 'block';
	}
}
function dimm(){
    for (j=1; j<= 10; j++){
        var obj = document.getElementById('o_uitleg_'+j);
        obj.style.display = 'none';
    }
}
function uitleg(i){
	dimm();
	var obj = document.getElementById('o_uitleg_'+i);
	obj.style.display = 'block';
}