function toggleSub(submenu) {
	//alert(submenu + ",display=" + document.getElementById(submenu).style.display + "!" );
	if (document.getElementById(submenu).style.display == 'none') {
		//alert("here: to block");
		document.getElementById(submenu).style.display = 'block';
		document.getElementById('img_' + submenu).src = './images/toggle_minus.gif';
	} else {
		//alert("or here: to none");
		document.getElementById(submenu).style.display = 'none';
		document.getElementById('img_' + submenu).src = './images/toggle_plus.gif';
	}
}