function change(x,item)
{

  //desmarca los anteriores
  document.getElementById("current").className = "";
  //marca el elemento actual
  item.className = "slideselected";

    

	document.getElementById("current").id = "";
	item.id = "current";
	if((x * (-1))<(getElementPosition("elementos").left - 10)){
		distance = (x + getElementPosition("elementos").left) / 5;
		start = getElementPosition("elementos").left;
		for(i=0; i<=distance; i++){
			setTimeout("document.getElementById(\"elementos\").style.margin = \"0 -" + ((start * (-1)) + (i*5)) + "px\"", i*5);
			if(i==distance){
				setTimeout("document.getElementById(\"elementos\").style.margin = \"0 -" + x + "px\"", i*5);
			}
		}
	}else if((x * (-1))>(getElementPosition("elementos").left)){
		distance = ((x + getElementPosition("elementos").left) / 5)  * (-1);
		start = getElementPosition("elementos").left;
		for(i=0; i<=distance; i++){
			setTimeout("document.getElementById(\"elementos\").style.margin = \"0 -" + ((start * (-1)) - (i*5)) + "px\"", i*5);
			if(i==distance)
				setTimeout("document.getElementById(\"elementos\").style.margin = \"0 -" + x + "px\"", i*5);
		}
	}
}
function getElementPosition(object){
	var position = new Object;
	position.left = parseInt(document.getElementById(object).style.marginLeft)
	position.top = parseInt(document.getElementById(object).style.marginTop)
	return position;
}

function startSlideShow(nSlides)
{
  // Fija el objeto inicial de la presentación
  var objSlide1 = document.getElementById("current");
  var dNow = new Date();
  var nowMinutes = dNow.getMinutes();
  var intInterval;
  
  intInterval = nowMinutes%nSlides;
  
  if(intInterval == 0)
    intInterval = 1;

  // presenta la diapositiva
  if(intInterval != 1)   
  {
    var objSlide = document.getElementById("slide"+intInterval);
    offset = (intInterval-1) * 520;
    change(offset,objSlide);
   }
   else
   {
    change(0,objSlide1); 
   }  
   

}