/**
 * Expand or collapse menu
 *
 * @param  {string}		eleId	element id of menu
 * @return {boolean}	false on success, true on fail
 */
function showMenu(eleId) {
	retValue = true;
	if(document.getElementById(eleId) != null) {
		// expand or collapse menu
		document.getElementById(eleId).style.display = (document.getElementById(eleId).style.display != "none") ? "none" : "block"
		retValue = false;
	}

	return retValue;
}