var agt=navigator.userAgent.toLowerCase();
      var is_major = parseInt(navigator.appVersion);
      var is_ie   = (agt.indexOf("msie") != -1);
      var is_ie3  = (is_ie && (is_major < 4));


      if (document.images) {
        onImages = new Array()
        onImages['obr0'] = new Image()
        onImages['obr0'].src = "sipka_on.gif"
        onImages['obr1'] = new Image()
        onImages['obr1'].src = "sipka_on.gif"
        onImages['obr2'] = new Image()
        onImages['obr2'].src = "sipka_on.gif"
        onImages['obr3'] = new Image()
        onImages['obr3'].src = "sipka_on.gif"
        onImages['obr4'] = new Image()
        onImages['obr4'].src = "sipka_on.gif"
        onImages['obr5'] = new Image()
        onImages['obr5'].src = "sipka_on.gif"
        onImages['obr6'] = new Image()
        onImages['obr6'].src = "sipka_on.gif"
        onImages['obr7'] = new Image()
        onImages['obr7'].src = "sipka_on.gif"
        onImages['obr8'] = new Image()
        onImages['obr8'].src = "sipka_on.gif"
        onImages['obr9'] = new Image()
        onImages['obr9'].src = "sipka_on.gif"
        onImages['obr10'] = new Image()
        onImages['obr10'].src = "sipka_on.gif"
        onImages['obr11'] = new Image()
        onImages['obr11'].src = "sipka_on.gif"
        onImages['obr12'] = new Image()
        onImages['obr12'].src = "sipka_on.gif"

        offImages = new Array()
        offImages['obr0'] = new Image()
        offImages['obr0'].src = "sipka.gif"
        offImages['obr1'] = new Image()
        offImages['obr1'].src = "sipka.gif"
        offImages['obr2'] = new Image()
        offImages['obr2'].src = "sipka.gif"
        offImages['obr3'] = new Image()
        offImages['obr3'].src = "sipka.gif"
        offImages['obr4'] = new Image()
        offImages['obr4'].src = "sipka.gif"
        offImages['obr5'] = new Image()
        offImages['obr5'].src = "sipka.gif"
        offImages['obr6'] = new Image()
        offImages['obr6'].src = "sipka.gif"
        offImages['obr7'] = new Image()
        offImages['obr7'].src = "sipka.gif"
        offImages['obr8'] = new Image()
        offImages['obr8'].src = "sipka.gif"
        offImages['obr9'] = new Image()
        offImages['obr9'].src = "sipka.gif"
        offImages['obr10'] = new Image()
        offImages['obr10'].src = "sipka.gif"
        offImages['obr11'] = new Image()
        offImages['obr11'].src = "sipka.gif"
        offImages['obr12'] = new Image()
        offImages['obr12'].src = "sipka.gif"

      }

      function xChange(imageName, newState) {
        if (document.images) {
          if (newState == "on")
              document.images[imageName].src = onImages[imageName].src
          else {
              document.images[imageName].src = offImages[imageName].src
          }
        }
      }