function revealemail(slt,mail)
{
   mail=unescape(mail);     
   res="";
   
   for (var i=0;i<mail.length;i++)
     {
       c=(mail.charCodeAt(i)-slt+256)%256;      
       res+=String.fromCharCode(c);
       slt=mail.charCodeAt(i);
     }

   return res;
}