function MoveLeft(size)
{
  //element arrays
  var elhr = $$('ul#portfolio li.hiddenright');
  var elhl = $$('ul#portfolio li.hiddenleft');
  var elvis = $$('ul#portfolio li.visible');
  var elt = $$('ul#portfolio li');
  
  //totals
  var telt = elt.length;
  var telhr = elhr.length;
  var telhl = elhl.length;
  var telvis = elvis.length;
  
 	var w = 0;
 	var toscroll = 6;

  //hoeveel elementen moeten er gescrolled worden ? 	
 	if ( (telt - telhr - telvis ) < toscroll ) {
 	  toscroll = telt - telhr - telvis;
 	}
 	
  for(var i=0; i<toscroll; i++){
		elvis[telvis - i - 1].className = 'hiddenright';
		elhl[i].className = 'visible';
	  w += 80;
	}
	
	if (w > 0) {
	  w += 25;
    new Effect.MoveBy('bigbox', 0, w ,
                                {
                                    duration: 0.6,
                                    transition: Effect.Transitions.sinoidal, queue: 'end'
                                });
	}          
      
}

function MoveRight(size)
{
  //element arrays
  var elhr = $$('ul#portfolio li.hiddenright');
  var elhl = $$('ul#portfolio li.hiddenleft');
  var elvis = $$('ul#portfolio li.visible');
  var elt = $$('ul#portfolio li');

  //totals
  var telt = elt.length;
  var telhr = elhr.length;
  var telhl = elhl.length;
  var telvis = elvis.length;
  
 	var w = 0;
 	var toscroll = 6;

  //hoeveel elementen moeten er gescrolled worden ? 	
 	if ( (telt - telhl - telvis ) < toscroll ) {
 	  toscroll = telt - telhl - telvis;
 	}
 	
  for(var i=0; i<toscroll; i++){
		elvis[telhr - i - 1].className = 'hiddenleft';
		elhr[i].className = 'visible';
	  w += 80;
	}
	
	if (w > 0) {
	  w += 25;
    new Effect.MoveBy('bigbox', 0, -w ,
                              {
                                  duration: 0.6,
                                  transition: Effect.Transitions.sinoidal, queue: 'end'
                              });
  }
                            
}