// check browser version
var NS = (navigator.appName.indexOf("Netscape")!=-1);
var MS = (navigator.appName.indexOf("Microsoft")!=-1);
var VER=parseInt(navigator.appVersion);
var CSS=((MS&&VER>=4)||(NS&&VER>=5));
var IE4=(MS&&VER==4);
var NS4 = (document.layers) ? 1 : 0;

var topID  = -1;

// constructor of menu elements
function menuConstructor (id, content)
{
        this.ID            = id;
        this.parentID      = content [0]*1;
        this.parentItemID  = content [1]*1;
        this.width         = content [2]*1;
        this.timerID       = -1;
        this.isOn          = false;
        this.item          = new Array ();
        this.currItemID    = -1;
        this.backColor     = content [6];

        if (this.parentID == -1)
        {
                this.x = initX + usedWidth;
//                usedWidth = usedWidth + this.width;
                usedWidth = 72 + usedWidth;
                this.y = initY;
        }
        else
        {
                this.y = content [3]*1;
                if (this.y < 0)
                        this.y =  menuElement [this.parentID].y
                                      + itemHeight*this.parentItemID
                                      + yOverlap;
                this.x = content [4]*1;
                if (this.x < 0)
                        this.x =  menuElement [this.parentID].x
                                      + menuElement [this.parentID].width
                                      - xOverlap;
        }
        items = content [5];

        layerBody = '<table width=' + this.width + ' cellpadding=3 cellspacing=' + borderSize + ' border=0>';
        
        for (j = 0; j <= items.length - 2; j = j + 2)
        {
                controlBlock = ' onMouseOver = "enterItem (' + this.ID + ', ' + ((j + 2)/2 - 1) + ');" onMouseOut = "exitItem (' + this.ID + ', ' + ((j + 2)/2 - 1) + ');" ';
                layerBody += '<td height=' + itemHeight + ' width=' + this.width + ' bgcolor=' + this.backColor + controlBlock + '><a style="font-family:arial; font-size:12px; color:black; text-decoration:none;" href='+ items [j + 1] +' ' + '>' + items [j] + '</a></td>';
                if (j < items.length - 2)
                        layerBody = layerBody +  '<tr>\n';
                else
                        layerBody = layerBody + '\n';
        }

        if (!NS4)
                layerHeader = '<div id=Menu' + this.ID +
                                           ' onMouseOver="enterMenu (' + this.ID + ');" onMouseOut = "exitMenu (' + this.ID + ');"' +
                               ' style="background:#ffffff ; width: ' + this.width + '; visibility: hidden; position: absolute; left: ' + this.x +
                                   '; top: ' + this.y + ';">';
        else
                layerHeader = '<layer id=Menu' + this.ID +
                                           ' onMouseOver="enterMenu (' + this.ID + ');" onMouseOut = "exitMenu (' + this.ID + ');"' +
                                           ' visibility=hide left=' + this.x +
                                           ' top =' + this.y + '>';

        layerHeader += '<table width=' + this.width + ' cellpadding=0 cellspacing=0 border=0>' +
                                    '<td bgcolor=' + borderColor + '>';

        layerFooter = '</table></td></table>';

        if (!NS4)
                layerFooter = layerFooter + '</div>';
        else
                layerFooter = layerFooter + '</layer>';

        document.writeln (layerHeader + layerBody + layerFooter);

        return this;
}
function enterTopItem (ID)
{
        if (topID != ID && topID != -1)
                hideTree (topID);
        releaseTree (ID);
        topID = ID;
        show (ID);
}
function exitTopItem (ID)
{
        menuElement [ID].timerID = setTimeout ('hide (' + ID + ')', delay);
}
function enterItem (menuID, itemID)
{
        var currItemID = menuElement [menuID].currItemID;

        if (currItemID != i & currItemID > -1)
                hide (currItemID);

        for (var i = 0; i < numOfMenus; i++)
        {
                if (menuElement [i].parentID == menuID &&
                    menuElement [i].parentItemID == itemID)
                {
                        clearTimeout (menuElement [i].timerID);
                        menuElement [i].timerID = -1;
                        show (i);
                        return 0;
                }
        }

        return -1;
}
function exitItem (menuID, itemID)
{
        for (var i = 0; i < numOfMenus; i++)
        {
                if (menuElement [i].parentID == menuID &&
                    menuElement [i].parentItemID == itemID)
                {
                        menuElement [i].timerID = setTimeout ('hide (' + i + ')', delay);
                        return 0;
                }
        }
}
function enterMenu (ID)
{
        var parentID = menuElement [ID].parentID;
        if (parentID == -1)
        {
                clearTimeout (menuElement [ID].timerID);
                menuElement [ID].timerID = -1;
        }
        else
                releaseTree (ID);
}
function exitMenu (ID)
{
        timeoutTree (ID);
}
function hideTree (ID)
{
        hide (ID);
        for (var j = 0; j < numOfMenus; j++)
        {
                if (menuElement [j].parentID == ID &&
                        menuElement [j].isOn)
                {
                        hideTree (j);
                        return 0;
                }
        }
}
function releaseTree (ID)
{
        clearTimeout (menuElement [ID].timerID);
        menuElement [ID].timerID = -1;

        var parentID = menuElement [ID].parentID;
        if (parentID > -1)
                releaseTree (parentID);
}
function timeoutTree (ID)
{
        menuElement [ID].timerID = setTimeout ('hide (' + ID + ')', delay);
        var parentID = menuElement [ID].parentID;
        if (parentID > -1)
                timeoutTree (parentID);
}

function show (ID)
{
        if (!NS4) {
                el = IE4 ? eval('Menu'+ID) : document.getElementById('Menu'+ID);
                el.style.visibility = "visible";
//                document.all['Menu' + ID].style.visibility = "visible";
        }
        else
                document.layers[ID].visibility = "visible";

        menuElement [ID].isOn = true;

        if (menuElement [ID].parentID > -1)
                menuElement [menuElement [ID].parentID].currItemID = ID;
}

function hide (ID)
{
        if (!NS4) {
                el = IE4 ? eval('Menu'+ID) : document.getElementById('Menu'+ID);
                el.style.visibility = "hidden";
//                document.all['Menu' + ID].style.visibility = "hidden";
        }
        else
                document.layers['Menu' + ID].visibility = "hide";

        menuElement [ID].isOn = false;

        if (menuElement [ID].parentID > -1)
                menuElement [menuElement [ID].parentID].currItemID = -1;
}

function createMenuTree ()
{
        for (var i = 0; i < menuContent.length; i++)
        {
                menuElement [i] = new menuConstructor (i, menuContent [i]);
                numOfMenus++;
        }
}

createMenuTree ();