/* Toggle display for GPS tutorial - JH */
function toggleDisplay(itemname)
{
   tmp = document.getElementsByTagName('div');
    for (i=0;i<tmp.length;i++)
    {
        if (tmp[i].className == itemname) tmp[i].style.display = (tmp[i].style.display == 'none' || tmp[i].style.display == '') ? 'block' : 'none';
    }
    
}