function changedcheckbox(chkbx)
{
	var elem;
	if (document.getElementById) {
		elem = document.getElementById('filters').style;
	} else if (document.all) {
		elem = document.all['filters'].style;
	} else if (document.layers) {
		elem = document.layers['filters'].style;
	}
	if (chkbx.checked==true) {
		elem.display='none';
	} else {
		elem.display='block';
	}
}