function bgcenter() {
  var theLaufband = $('laufband1');
  var theOffset = Math.floor(($('body').getWidth() - 1000) / 2) + 6;
  
  theLaufband.setStyle({
      'left' : theOffset + 'px'
    });
}

document.observe("dom:loaded", function() {
	/* init scroller */
	initScroller($('wslider'));
	bgcenter();
});

Event.observe(window, "resize", bgcenter);