var isDOM = (document.getElementById ? true : false); 
var isIE4 = ((document.all && !isDOM) ? true : false);
var isNS4 = (document.layers ? true : false);

function getRef(id) 
{
   if (isDOM) 
      return document.getElementById(id); 
   if (isIE4) 
      return document.all[id];
   if (isNS4) 
      return document.layers[id];
}

function getSty(id) 
{
   return (isNS4 ? getRef(id) : getRef(id).style);
} 

// Hide timeout.
var popTimer = 0;
// Array showing highlighted menu items.
var litNow = new Array();

function popOver(menuNum, itemNum) 
{
   clearTimeout(popTimer);
   hideAllBut(menuNum);
   litNow = getTree(menuNum, itemNum);
   changeCol(litNow, true);
   targetNum = menu[menuNum][itemNum].target;
   if (targetNum > 0) 
   {
      thisX = parseInt(menu[menuNum][0].ref.left) + parseInt(menu[menuNum][itemNum].ref.left);
      thisY = parseInt(menu[menuNum][0].ref.top) + parseInt(menu[menuNum][itemNum].ref.top);
      with (menu[targetNum][0].ref) 
      {
         left = parseInt(thisX + menu[targetNum][0].x);
         top = parseInt(thisY + menu[targetNum][0].y);
         visibility = 'visible';
      }
   }
}

function popOut(menuNum, itemNum) 
{
   if ((menuNum == 0) && !menu[menuNum][itemNum].target)
      hideAllBut(0)
   else
      popTimer = setTimeout('hideAllBut(0)', 500);
}

function getTree(menuNum, itemNum) 
{
// Array index is the menu number. The contents are null (if that menu is not a parent)
// or the item number in that menu that is an ancestor (to light it up).
   itemArray = new Array(menu.length);

   while(1) 
   {
      itemArray[menuNum] = itemNum;
// If we've reached the top of the hierarchy, return.
   if (menuNum == 0) 
      return itemArray;
   itemNum = menu[menuNum][0].parentItem;
   menuNum = menu[menuNum][0].parentMenu;
   }
}

// Pass an array and a boolean to specify colour change, true = over colour.
function changeCol(changeArray, isOver) 
{
   for (menuCount = 0; menuCount < changeArray.length; menuCount++) 
   {
      if (changeArray[menuCount]) 
      {
         newCol = isOver ? menu[menuCount][0].overCol : menu[menuCount][0].backCol;
// Change the colours of the div/layer background.
         with (menu[menuCount][changeArray[menuCount]].ref) 
         {
            if (isNS4) 
               bgColor = newCol;
            else 
               backgroundColor = newCol;
         }
      }
   }
}

function hideAllBut(menuNum) 
{
   var keepMenus = getTree(menuNum, 1);
   for (count = 0; count < menu.length; count++)
      if (!keepMenus[count])
         menu[count][0].ref.visibility = 'hidden';
   changeCol(litNow, false);
}

// *** MENU CONSTRUCTION FUNCTIONS ***

function Menu(isVert, popInd, x, y, width, overCol, backCol, borderClass, textClass) 
{
// True or false - a vertical menu?
   this.isVert = isVert;
// The popout indicator used (if any) for this menu.
   this.popInd = popInd
// Position and size settings.
   this.x = x;
   this.y = y;
   this.width = width;
// Colours of menu and items.
   this.overCol = overCol;
   this.backCol = backCol;
// The stylesheet class used for item borders and the text within items.
   this.borderClass = borderClass;
   this.textClass = textClass;
// Parent menu and item numbers, indexed later.
   this.parentMenu = null;
   this.parentItem = null;
// Reference to the object's style properties (set later).
   this.ref = null;
}

function Item(text, href, click, param, frame, length, spacing, target) 
{
   this.text = text;
   this.href = href;
   this.click = click;
   this.param = param;
   this.frame = frame;
   this.length = length;
   this.spacing = spacing;
   this.target = target;
// Reference to the object's style properties (set later).
   this.ref = null;
}

var menu;

function LoadMenuBar(spacing)
{
   menu = new Array();

// Default colours passed to most menu constructors (just passed to functions, not
// a global variable - makes things easier to change later in bulk).
   var defOver = '#6060FF', defBack = '#3030FF';
   var cOver = '#005388', cBack = '#00A6FF';
   var pOver = '#604927', pBack = '#B6934E';
   var mOver = '#355836', mBack = '#69AF6C'; 

// Default 'length' of menu items - item height if menu is vertical, width if horizontal.
   var defLength = 17;
   var defWidth = 150;

// Menu 0 is the special, 'root' menu from which everything else arises.
   menu[0] = new Array();
// A non-vertical menu with a few different colours and no popout indicator, as an example.
// *** MOVE ROOT MENU AROUND HERE ***  it's positioned at (160, 76) and is 17px high now.
//   menu[0][0] = new Menu(false, '', 160, 76, defLength, defBack, defBack, '', 'itemText');
   menu[0][0] = new Menu(false, '', 255, 76, defLength, '', '', '', 'itemText');
// Notice how the targets are all set to nonzero values...
// The 'length' of each of these items is 150, and there is spacing of 0 to the next item.
// Most of the links are set to '#' hashes, make sure you change them to actual files.
   menu[0][1] = new Item('Contacts & Orders', '#', '', '', '', defWidth, 0, 1);
   menu[0][2] = new Item('Products & Prices', '#', '', '', '', defWidth, 0, 2);
   menu[0][3] = new Item('Downloads', '#', '', '', '', defWidth, 0, 3);

// Contacts & Orders menu.
   menu[1] = new Array();
// The File menu is positioned 0px across and 17 down from its trigger, and is 200 wide.
// All text in this menu has the stylesheet class 'item' -- see the <style> section above.
   menu[1][0] = new Menu(true, '', 0, 17, defWidth, defOver, defBack, 'itemBorder', 'itemText');
   menu[1][1] = new Item('Home Page', 'index.html', '', '', '', defLength, 0, 0);
   menu[1][2] = new Item('About Datasonics', 'aboutds.html', '', '', '', defLength, 0, 0);
   menu[1][3] = new Item('Getting in Touch', 'contact.html', '', '', '', defLength, 0, 0);
   menu[1][4] = new Item('Cool Links', 'links.html', '', '', '', defLength, 0, 0);
   menu[1][5] = new Item('New Order', 'neworder.html', '', '', '', defLength, 0, 0);
   menu[1][6] = new Item('Update Order', 'updorder.html', '', '', '', defLength, 0, 0);
   menu[1][7] = new Item('Registration', 'rego.html', '', '', '', defLength, 0, 0);

// Products & Prices menu.
   menu[2] = new Array();
   menu[2][0] = new Menu(true, '', 0, 17, defWidth, defOver, defBack, 'itemBorder', 'itemText');
   menu[2][1] = new Item('Music Master Info', 'mm.html', '', '', '', defLength, 0, 0);
   menu[2][2] = new Item('Mastering Music Info', 'mmlessons.html', '', '', '', defLength, 0, 0);
   menu[2][3] = new Item('VS Pro Info', 'vspro.html', '', '', '', defLength, 0, 0);
   menu[2][4] = new Item('Product Prices', 'distrib.html', '', '', '', defLength, 0, 0);
   menu[2][5] = new Item('Frequent Questions', 'http://www.datasonics.com.au/cgi-bin/faqmain.pl?page=0', '', '', '', defLength, 0, 0);

// Downloads menu
   menu[3] = new Array();
   menu[3][0] = new Menu(true, '', 0, 17, defWidth, defOver, defBack, 'itemBorder', 'itemText');
   menu[3][1] = new Item('Music Master Demo', 'mmdemorego.html', '', '', '', defLength, 0, 0);
   menu[3][2] = new Item('Mastering Music Demo', 'mmlessonsdemo.html', '', '', '', defLength, 0, 0);
   menu[3][3] = new Item('VS Pro Demo', 'vsdemorego.html', '', '', '', defLength, 0, 0);
   menu[3][4] = new Item('Demo Songs', 'songs.html', '', '', '', defLength, 0, 0);
   menu[3][5] = new Item('Direct X', 'http://www.microsoft.com/directx/homeuser/downloads/default.asp', '', '', '', defLength, 0, 0);

   var popOldWidth = window.innerWidth;
   nsResizeHandler = new Function('if (popOldWidth != window.innerWidth) location.reload()');

   if (isNS4) 
   {
      document.captureEvents(Event.CLICK);
   }
   document.onclick = clickHandle;
}


function DisplayMenuBar(spacing) 
{
   var currMenu;
   var currItem;
	
   for (currMenu = 0; currMenu < menu.length; currMenu++) with (menu[currMenu][0]) 
   {
// Variable for holding HTML for items and positions of next item.
      var str = '', itemX = 0, itemY = 0;

// Remember, items start from 1 in the array (0 is menu object itself, above).
// Also use properties of each item nested in the other with() for construction.

      for (currItem = 1; currItem < menu[currMenu].length; currItem++) with (menu[currMenu][currItem]) 
      {
         var itemID = 'menu' + currMenu + 'item' + currItem;

// The width and height of the menu item - dependent on orientation!
         var w = (isVert ? width : length);
         var h = (isVert ? length : width);

         if (isDOM || isIE4) 
         {
            str += '<div id="' + itemID + '" style="position: absolute; z-index:999; left: ' + itemX + '; top: ' + itemY + '; width: ' + w + '; height: ' + h + '; visibility: inherit; ';
            if (backCol) 
               str += 'background: ' + backCol + '; ';
            str += '" ';
         }
         if (isNS4) 
         {
            str += '<layer id="' + itemID + '" left="' + itemX + '" top="' + itemY + '" width="' +  w + '" height="' + h + '" visibility="inherit" ';
            if (backCol) 
               str += 'bgcolor="' + backCol + '" ';
         }
         if (borderClass) 
            str += 'class="' + borderClass + '" ';

// Add mouseover handlers and finish div/layer.
         str += 'onMouseOver="popOver(' + currMenu + ',' + currItem + ')" onMouseOut="popOut(' + currMenu + ',' + currItem + ')"';
         if (click)
         {
            str += 'onclick="'
            str += click;
            str += '('
            if (param)
            {
               str += "'";
               str += param;
               str += "'";
            }
            str += ')" ';
         }
         str += '>'
// Add contents of item (default: table with link inside).
// In IE/NS6+, add padding if there's a border to emulate NS4's layer padding.
// If a target frame is specified, also add that to the <a> tag.

         str += '<table width="' + (w - 8) + '" border="0" cellspacing="0" cellpadding="' + (!isNS4 && borderClass ? 3 : 0) + '"><tr><td align="left" height="' + (h - 7) + '">' + '<a class="' + textClass + '" href="' + href + '"' + (frame ? ' target="' + frame + '">' : '>') + text + '</a></td>';
         if (target > 0) 
         {
// Set target's parents to this menu item.
            menu[target][0].parentMenu = currMenu;
            menu[target][0].parentItem = currItem;

// Add a popout indicator.
            if (popInd) 
               str += '<td class="' + textClass + '" align="right">' + popInd + '</td>';
         }
         str += '</tr></table>' + (isNS4 ? '</layer>' : '</div>');
         if (isVert)
            itemY += length + spacing;
         else 
            itemX += length + spacing;
      }

      if (isDOM) 
      {
         var newDiv = document.createElement('div');
         document.getElementsByTagName('body').item(0).appendChild(newDiv);
         newDiv.innerHTML = str;
         ref = newDiv.style;
         ref.position = 'absolute';
         ref.visibility = 'hidden';
         ref.zIndex = 16;
      }

// Insert a div tag to the end of the BODY with menu HTML in place for IE4.
      if (isIE4) 
      {
         document.body.insertAdjacentHTML('beforeEnd', '<div id="menu' + currMenu + 'div" ' +          'style="position: absolute; visibility: hidden">' + str + '</div>');
         ref = getSty('menu' + currMenu + 'div');
      }

// In NS4, create a reference to a new layer and write the items to it.
      if (isNS4) 
      {
         ref = new Layer(0);
         ref.document.write(str);
         ref.document.close();
      }

      for (currItem = 1; currItem < menu[currMenu].length; currItem++) 
      {
         itemName = 'menu' + currMenu + 'item' + currItem;
         if (isDOM || isIE4) 
            menu[currMenu][currItem].ref = getSty(itemName);
         if (isNS4) 
            menu[currMenu][currItem].ref = ref.document[itemName];
      }
   }
   with(menu[0][0]) 
   {
      ref.left = x;
      ref.top = y;
      ref.visibility = 'visible';
   }
}

function writeMenuBar(spacing) 
{
   if (!isDOM && !isIE4 && !isNS4) 
      return;

   LoadMenuBar(spacing);
   DisplayMenuBar(spacing);
//   document.body.scroll="no";
//   document.onkeyup = keyUp;
}

function clickHandle(evt)
{
 if (isNS4) document.routeEvent(evt);
 hideAllBut(0);
}

// This is just the moving command for the example.

function moveRoot()
{
   with(menu[0][0].ref) left = ((parseInt(left) < 100) ? 100 : 5);
}