function select_all()
{
	var i = 1;
	while(true)
	{
		var id = "cb_" + i;

		try
		{
			document.getElementById(id).checked = true;
			i++;
		}
		catch(e)
		{
			break;
		}
	}
}

function toggle(hideid, showid)
{
  document.getElementById(hideid).style.display = 'none';
  document.getElementById(showid).style.display = 'block';
}