String.prototype.startsWith = function(str) {
  return (this.match("^"+str)==str)
}

function hideAllSubs(node, exceptionName) {
  if (node.hasChildNodes()) {
     var children = node.childNodes;
     for (var i = 0; i < children.length; i++) {
       var divId = children[i].id;
       if (divId && divId.startsWith("sub")) {
         if (divId == exceptionName) {
           children[i].className = "visibleSubMenu";
         } else {
            children[i].className = "invisibleSubMenu";
         }
       }
     }  
   }
}


function inactivateAllMenus(node, exceptionName) {
  if (node.hasChildNodes()) {
     var children = node.childNodes;
     for (var i = 0; i < children.length; i++) {
       // Doorzoek de kinderen van dit kind recursief
       inactivateAllMenus(children[i], exceptionName);

       // En kijk of we een page menu item te pakken hebben
       if (children[i].className == "pageMenuItemActive" || children[i].className == "pageMenuItemInactive")   {
         if (children[i].id==exceptionName) {
           children[i].className = "pageMenuItemActive";
         } else {
            children[i].className = "pageMenuItemInactive";
         }
       }
     }
   }
}


function showMenu(menuId) {
   inactivateAllMenus( document.getElementById("mainmenu"), "main"+menuId);
   hideAllSubs(document.getElementById("submenu"), "sub"+menuId);
}


function showMenuOnStart(menuId) {
   setTimeout(function() {showMenu(menuId)}, 300);
}