unternehmenon = new Image();
  unternehmenon.src = "images/nav_dianormunternehmen_on.gif";
  unternehmenoff = new Image();
  unternehmenoff.src = "images/nav_dianormunternehmen_off.gif";
  
  produkteon = new Image();
  produkteon.src = "images/nav_dianormprodukte_on.gif";
  produkteoff = new Image();
  produkteoff.src = "images/nav_dianormprodukte_off.gif";

  aktuelleson = new Image();
  aktuelleson.src = "images/nav_dianormaktuelles_on.gif";
  aktuellesoff = new Image();
  aktuellesoff.src = "images/nav_dianormaktuelles_off.gif";

  serviceon = new Image();
  serviceon.src = "images/nav_dianormservice_on.gif";
  serviceoff = new Image();
  serviceoff.src = "images/nav_dianormservice_off.gif";

  kontakton = new Image();
  kontakton.src = "images/meta_dianormkontakt_on.gif";
  kontaktoff = new Image();
  kontaktoff.src = "images/meta_dianormkontakt_off.gif";

  sitemapon = new Image();
  sitemapon.src = "images/meta_dianormsitemap_on.gif";
  sitemapoff = new Image();
  sitemapoff.src = "images/meta_dianormsitemap_off.gif";

  impressumon = new Image();
  impressumon.src = "images/meta_dianormimpressum_on.gif";
  impressumoff = new Image();
  impressumoff.src = "images/meta_dianormimpressum_off.gif";

  searcharrowon = new Image();
  searcharrowon.src = "images/nav_dianormsuche_pfeil_on.gif";
  searcharrowoff = new Image();
  searcharrowoff.src = "images/nav_dianormsuche_pfeil_off.gif";

  produktneuheitenon = new Image();
  produktneuheitenon.src = "/produktneuheiten_on.gif";
  produktneuheitenoff = new Image();
  produktneuheitenoff.src = "/produktneuheiten_off.gif";

  nachobenon = new Image();
  nachobenon.src = "images/top_dianormpfeil_on.gif";
  nachobenoff = new Image();
  nachobenoff.src = "images/top_dianormpfeil_off.gif";

  umbauon = new Image();
  umbauon.src = "/umbau_on.gif";
  umbauoff = new Image();
  umbauoff.src = "/umbau_off.gif";
 
function Nav() {
    this.children = new Array();
    this.addChild = function(id,href,label) {
        this.children[this.children.length] = new NavElement(id,href,label,this);
        this.lastChild = this.children[this.children.length - 1];
    }
    this.getChildById = function(id) {
        var i;
        for (i=0;i<this.children.length;i++) {
            if (this.children[i].id == id) {
                return this.children[i];
            } else if (this.children[i].children.length > 0) {
                if (this.children[i].getChildById(id)) return this.children[i].getChildById(id);
            }
        }
    }
    this.setActive = function(id) {
        var navElem = this.getChildById(id);
        if (!navElem) {
            navElem = this;
        } else {
            navElem.active = true;
            navElem.selected = true;
            navElem = navElem.parent;
            while (navElem.parent) {
                navElem.selected = true;
                navElem = navElem.parent;
            }
        }
    }
    this.printAll = function() {
        var i;
        var output = '';
        for (i=0;i<this.children.length;i++) {
            if (this.children[i].selected || this.children[i].active) {
                output += '<img src="images/nav2_pfeil.gif" border="0" hspace="10"><a class="subnaviaktiv" href="' + this.children[i].href + '">' + this.children[i].label + '</a><br>';
                output += '<img src="images/nav2_trenner.gif" border="0" vspace="5" hspace="10"><br>';
                if (this.children[i].children.length > 0) {
                    output += this.children[i].printSub();
                    output += '<img src="/leer.gif" height="30" width="1" border="0"><br>';
                    if (this.children.length - 1 != i) {
                        output += '<img src="images/nav2_trenner.gif" border="0" vspace="5" hspace="10"><br>';
                    }
                }
            } else {
                output += '<img src="images/nav2_pfeil.gif" border="0" hspace="10"><a class="subnavi" href="../DiaNorm - Heizkörper - Home_files/' + this.children[i].href + '">' + this.children[i].label + '</a><br>';
                if (this.children.length - 1 == i) {
                    output += '<img src="/leer.gif" height="3" width="1" border="0" vspace="5" hspace="10"><br>';
                } else {
                    output += '<img src="images/nav2_trenner.gif" border="0" vspace="5" hspace="10"><br>';
                }
            }
        }
        document.getElementById('navigation').innerHTML = output;
    }
}
function NavElement(id,href,label,parent) {
    this.href = href;
    this.label = label;
    this.parent = parent;
    this.images = this.parent.images;
    this.id = id;
    this.active = false;
    this.selected = false;
    this.children = new Array();
    this.addChild = function(id,href,label) {
        this.children[this.children.length] = new NavElement(id,href,label,this);
        this.lastChild = this.children[this.children.length - 1];
    }
    this.getChildById = function(id) {
        var i;
        for (i=0;i<this.children.length;i++) {
            if (this.children[i].id == id) {
                return this.children[i];
            } else if (this.children[i].children.length > 0) {
                if (this.children[i].getChildById(id)) return this.children[i].getChildById(id);
            }
        }
    }
    this.printSub = function() {
        var i;
        var out = '';
        var showSub;
        var navElem;
        for (i=0;i<this.children.length;i++) {
            out += '';
            navElem = this.children[i];
   if (navElem.children.length == 0) {
    showSub = false;
   } else if (navElem.selected) {
    showSub = true;
   } else {
    showSub = false;
   }
            if (navElem.active || navElem.selected) {
                out += '<a class="subnavi2aktiv" href="' + navElem.href + '">' + navElem.label + '</a><br>';
            } else {
                out += '<a class="subnavi2" href="' + navElem.href + '">' + navElem.label + '</a><br>';
            }
            if (showSub) {
                out += '<div style="margin-left:15px">' + navElem.printSub() + '</div>';
            }
        }
        return out;
    }
    this.getRoot = function() {
        var navElem = this;
        while (navElem.parent) {
            navElem = navElem.parent;
        }
        return navElem;
    }
}

    firstMenu = "";
    secondMenu = "";
    thirdMenu = "";
    menuVisible = "off";

    function setMenuVisible() {
        menuVisible = "on";
    }
  
    function setMenuInvisible() {
        menuVisible = "off";
    }
  
    function checkMenuVisible() {
        if (menuVisible == "off") clearFirst();
    }

    function clearFirst() {
        if (firstMenu != "") {
            document.getElementById(firstMenu).style.visibility = "hidden";
            firstMenu = "";
            clearSecond();
        }
    }

    function clearSecond() {
        if (secondMenu != "") {
            document.getElementById(secondMenu).style.visibility = "hidden";
            document.getElementById("a" + secondMenu).className = "inaktiv";
            secondMenu = "";
            clearThird();
        }
    }

    function clearThird() {
        if (thirdMenu != "") {
            document.getElementById(thirdMenu).style.visibility = "hidden";
            document.getElementById("a" + thirdMenu).className = "inaktiv";
            thirdMenu = "";
        }
    }
  
    function showFirst(level) {
        if (firstMenu != level) clearFirst();
        firstMenu = level;
        document.getElementById(level).style.visibility = "visible";
    }

    function showSecond(level) {
        if (level != secondMenu) clearSecond();
        secondMenu = level;
        document.getElementById("a" + secondMenu).className = "aktiv";
        document.getElementById(level).style.visibility = "visible";
    }

    function showThird(level) {
        if (level != thirdMenu) clearThird();
        thirdMenu = level;
        document.getElementById("a" + thirdMenu).className = "aktiv";
        document.getElementById(level).style.visibility = "visible";
    }