String.prototype.rot = function(){
    return this.replace(/[a-zA-Z]/g, function(c){
        return String.fromCharCode((c <= "Z" ? 90 : 122) >= (c = c.charCodeAt(0) + 13) ? c : c - 26);
    });
};

function mto() {
   var d = "ofn350.bet";
   var m = "znvygb";
   var e;
   var aSpans = new Array();

   aSpans = document.getElementsByTagName("span");
   for (i=0; i<aSpans.length; i++) {
      if (aSpans[i].className && aSpans[i].className=='mt') {
         // alert("Span found.");
         e = aSpans[i].innerHTML + "&#64;" + d.rot();
         aSpans[i].innerHTML = "<a href=\"" + m.rot() + ":" + e + "\">" + e + "</a>";
      }
   }
}