numMenus = 5;
document.onmouseover = hideAllMenus;

function getStyleObject(objectId) {
   if(document.getElementById && document.getElementById(objectId)) {
      return document.getElementById(objectId).style;
   } else if (document.all && document.all(objectId)) {
      return document.all(objectId).style;
   } else if (document.layers && document.layers[objectId]) {
      return document.layers[objectId];
   } else {
      return false;
   }
}

function changeObjectVisibility(objectId, newVisibility) {
   var styleObject = getStyleObject(objectId);
   if(styleObject) {
      styleObject.visibility = newVisibility;
      return true;
   } else {
      return false;
   }
}


function showMenu(menuNumber, eventObj) {
   hideAllMenus();
   eventObj.cancelBubble = true;
   var menuId = 'jsMenu' + menuNumber;
   if(changeObjectVisibility(menuId, 'visible')) {
      return false;
   } else {
      return true;
   }
}

function hideAllMenus() {
   for(counter = 1; counter <= numMenus; counter++) {
      changeObjectVisibility('jsMenu' + counter, 'hidden');
   }
}