var ag = navigator.userAgent;
var agl = ag.toLowerCase();
var fixer = ((agl.indexOf("msie") != -1) && (agl.indexOf("konqueror") == -1));

function extH( num ) {
   if (fixer) {
      var sm = document.getElementById('ext_links' + num);
      sm.style.display = "block";
   }
}

function extO( num ) {
   if (fixer) {
     var sm = document.getElementById('ext_links' + num);
     sm.style.display = "none";
   }
}