document.body.className+=' js';
function vis(id,ctr,fl)
{
	if(fl==1) ctr = id + ctr;
	else ctr = id + ctr * 2;
	for(i=id;i<ctr;i++)
	{
		str="block_"+i;
		if(document.getElementById(str).className == '')document.getElementById(str).className = 'hidden';
		else document.getElementById(str).className = '';
	}
}