var base64		= {
 charmap		: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
 encode			: function(str) {
  var ret		= "";
  var c, i, acc		= 0;
  var div		= 1;
  for(i=0,c=0;i<str.length;i++,c++) {
   acc			= acc*256 + str.charCodeAt(i);
   div			= div*4;
   ret			= ret + base64.charmap.charAt(parseInt(acc/div));
   acc			= acc % div;
   if(div==64) ret	= ret + base64.charmap.charAt(parseInt(acc)), acc = 0, div = 1,c++;
   if(c>=75) c=-1, ret	= ret + "\n";
  } if(i%3) {
   ret			= ret + base64.charmap.charAt(parseInt(acc*((i%3==1)?16:4)));
   ret			= ret + ((i%3)==1?"==":"=");
  } return ret;
 },
 decode			: function(str) {
  var ret		= "";
  var i, acc		= 0;
  var div		= 1;
  for(i=0;i<str.length;i++) {
   if(str.charAt(i)=="=" || str.charAt(i)=='\n') break;
   acc			= acc*64 + base64.charmap.indexOf(str.charAt(i));
   div			= (div==1?64:div/4);
   if(div!=64) {
    ret			= ret + String.fromCharCode(parseInt(acc/div));
    acc			= acc % div;
   }
  } return ret;
 }
}

e = 'PGEgaHJlZj0ibWFpbHRvOm1lZGlhY29udGFjdEBteXN0cmVuZ3RoZm9ybGlmZS5jb20iPk1lZGlhIENvbnRhY3Q8L2E+';
document.write(base64.decode(e));