function changeTab(obj, idTab) {
	var li = obj.parentNode;
	var ul = li.parentNode;
	var elements = ul.getElementsByTagName('li');	  

	for (var i = 0; i < elements.length; i++) {
		if (i == idTab) {
			document.getElementById('tab_' + i).style.display = 'block';
			//document.getElementById('tab_' + i).className = 'leftbox active';
			elements[i].className += ' active'; 
		}
		else
		{
			document.getElementById('tab_' + i).style.display = 'none';
			//document.getElementById('tab_' + i).className = 'leftbox';
			elements[i].className = '';
		}
	}
	
}