//onload=function() {
//setInterval('OMAR_Blink()',500);
//}

function OMAR_Blink() {
 if (!document.all) return;
 else {
   for(i=0;i<document.all.tags('blink').length;i++){
      s=document.all.tags('blink')[i];
      s.style.visibility=(s.style.visibility=='visible')?'hidden':'visible';
   }
 }
}

function addEvent(obj, evType, fn){ 
if (obj.addEventListener){ 
obj.addEventListener(evType, fn, false); 
return true; 
} else if (obj.attachEvent){ 
var r = obj.attachEvent("on"+evType, fn); 
return r; 
} else { 
return false; 
} 
} 

addEvent(window, 'load', OMAR_Blink);
setInterval('OMAR_Blink()',500);