// initialize the menu
function initialize ()
  {
    var iCount;
    var iIndex;
    var sMenu;
    var a_sImages;
    var objImage;
    if (document.images)
      {
        // create an array of the necessary images
        a_sImages = new Array ();
        a_sImages["menu"] = ["collection", "current_exhibitions", "v22plc", "contact", 'studios'];
        switch (document.sMenuHighlight)
          {
            case "collection":
              a_sImages["submenu"] = ["catalogue", "artists", "collection", "news", "projects"];
              break;
            case "current_exhibitions":
              a_sImages["submenu"] = ["current", "past"];
              break;
            case "contact":
              a_sImages["submenu"] = ["contact", "register", "feedback"];
              break;
            default:
              a_sImages["submenu"] = [];
              break;
          }
        a_sImages["footer"] = ["about", "legal", "help"];
        // preload the images
        document.a_objImages = new Array ();
        iIndex = 0;
        for (sMenu in a_sImages)
          {
            for (iCount = 0; iCount < a_sImages[sMenu].length; iCount++)
              {
                objImage = new Image ();
                objImage.src = "/png/" + sMenu + "/" + a_sImages[sMenu][iCount] + "_on.png";
                document.a_objImages[iIndex] = objImage;
                iIndex++;
              }
          }
      }
  }

// swap the image
function swapImage (sMenu, sName, sSuffix)
  {
    var sID;
    var objImage;
    objImage = getElement ("image_" + sMenu + "_" + sName);
    if (objImage)
      {
        objImage.src = "/png/" + sMenu + "/" + sName + "_" + sSuffix + ".png";
      }
  }

// get an element
function getElement (sID)
  {
    var objElement;
    if (document.getElementById)
      {
        objElement = document.getElementById (sID);
      }
    if (!objElement && document.all)
      {
        objElement = document.all[sID];
      }
    if (!objElement)
      {
        objElement = document[sID];
      }
    return objElement;
  }