function changeClass(obj, new_class)
{
    obj.className = new_class;
}

function changeBgColor(obj, new_color)
{
	obj.style.backgroundColor=new_color;
}

function changePic(name, pic)
{
	name.src = pic;
}

function createPopup(target, width, height)
{
	window.open('', target, 'width=' + width + ', height=' + height).moveTo((screen.width - width) / 2, (screen.height - height) / 2);
}

function prikaziSkrij(id)
{
	el = document.getElementById(id);
  if(el.style.display == '')
    el.style.display = 'block';
  else
    el.style.display = '';
}