// From http://www.prodevtips.com/2008/10/21/jquery-plugin-html-decode-and-encode/
jQuery.fn.encHTML = function() { 
  return this.each(function(){ 
    var me   = jQuery(this); 
    var html = me.html(); 
    if(jQuery.fn.isEncHTML(html)) return;
    me.html(html.replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;')); 
  }); 
}; 
 
jQuery.fn.decHTML = function() { 
  return this.each(function(){ 
    var me   = jQuery(this); 
    var html = me.html(); 
    me.html(html.replace(/&amp;/g,'&').replace(/&lt;/g,'<').replace(/&gt;/g,'>')); 
  }); 
}; 
 
jQuery.fn.isEncHTML = function(str) { 
  if(str.search(/&amp;/g) != -1 || str.search(/&lt;/g) != -1 || str.search(/&gt;/g) != -1) 
    return true; 
  else 
    return false; 
}; 
 
jQuery.fn.decHTMLifEnc = function(){ 
  return this.each(function(){ 
    var me   = jQuery(this); 
    var html = me.html(); 
    if(jQuery.fn.isEncHTML(html)) 
      me.html(html.replace(/&amp;/g,'&').replace(/&lt;/g,'<').replace(/&gt;/g,'>')); 
  }); 
};