function newImage( imgSrc )  {

 var imgName = new Image();
 imgName.src = imgSrc;

 return imgName;
}

function change( imgName, imgLocation )  {
  document[imgName].src = imgLocation;
}

var preloadFlag = false;

function loadImages()  {
  if (document.images)  {
    phone_over = newImage("/image/phoneNav-over.gif");
    about_over = newImage("/image/aboutNav-over.gif");
    sales_over = newImage("/image/salesNav-over.gif");
    support_over = newImage("/image/supportNav-over.gif");
    partner_over = newImage("/image/partnerNav-over.gif");
    dealer_over = newImage("/image/dealerNav-over.gif");

    preloadFlag = true;
  }
}

function changeNav(nav, over)  {
  var imgName;
  var imgLocation = "/image/";

  if(nav == "aboutUs")  {
    imgName = "primeNav2";
    imgLocation += "aboutNav";
  }
  else if(nav == "sales")  {
    imgName = "primeNav3";
    imgLocation += "saleNav";
  }
  else if(nav == "support")  {
    imgName = "primeNav4";
    imgLocation += "supportNav";
  }
  else if(nav == "partner")  {
    imgName = "primeNav5";
    imgLocation += "partnerNav";
  }
  else if(nav == "dealer")  {
    imgName = "primeNav6";
    imgLocation += "dealerNav";
  }
  else  {
    imgName = "primeNav1";
    imgLocation += "phoneNav";
  }

  if(over == 1)  {
    imgLocation += "-over";
  }
  else if(over == 2)  {
    imgLocation += "-on";
  }

  imgLocation += ".gif";

  change(imgName, imgLocation);
}