function blinker() {
     for(i=0; i<document.getElementsByTagName("span").length; i++) {
          if(document.getElementsByTagName("span")[i].style.visibility != "hidden") {
               if(document.getElementsByTagName("span")[i].className.substr(0, 5) == "blink") document.getElementsByTagName("span")[i].style.visibility = "hidden";
          } else {
               if(document.getElementsByTagName("span")[i].className.substr(0, 5) == "blink") document.getElementsByTagName("span")[i].style.visibility = "visible";
          }
          }
     var zeit = 750;
     window.setTimeout("blinker()", zeit);
}