function hideMainMenu() {
	document.getElementById("mainmenu_01").style.display="none";
	document.getElementById("mainmenu_02").style.display="none";
};


function hideSubMenu() {
	document.getElementById("submenu_01").style.display="none";
	document.getElementById("submenu_02").style.display="none";
	document.getElementById("submenu_03").style.display="none";
	/* document.getElementById("submenu_04").style.display="none"; */
	/* document.getElementById("submenu_05").style.display="none"; */
	document.getElementById("submenu_06").style.display="none";
	document.getElementById("submenu_07").style.display="none";
	document.getElementById("submenu_08").style.display="none";
	/* document.getElementById("submenu_09").style.display="none"; */
};


function showAndHideMenu(targetMenuID) {
	// check to see if the target menu is hidden or visible
	var attributeValue = document.getElementById(targetMenuID).style.display;
	
	if(targetMenuID == "mainmenu_01" || targetMenuID == "mainmenu_02") {
		hideMainMenu();
	};
	
	hideSubMenu();
	
	// if its hidden, show it
	if(targetMenuID == "submenu_04" || targetMenuID == "submenu_05" || targetMenuID == "submenu_09") {
		return;
	} else {
		if(attributeValue == "none") {
			document.getElementById(targetMenuID).style.display="block";
		} else { // if its visible, hide it
			document.getElementById(targetMenuID).style.display="none";
		};
	};
};