function moveto(id, size)
{
    obj = document.getElementById(id);
    position = obj.style.top;

    position = clearPosition(position);
    position = (position*1) + (size*1);

    if(minleft>=position && position>maxleft)
    {
        obj.style.top = position + 'px';
    }

}

function clearPosition(pos){
    if(pos){
        return pos.replace('px','');
    } else {
        return 0;
    }
}

// Variables de configuración
var numitems = 10;
var numxview = 1;
var sizeitem = 70;
var maxleft  = sizeitem*numitems*(-1);
var minleft  = 0;