How do I get alternate style sheets to work on iOS5 Safari?

I have been working on a HTML5 app for the iPad. Part of the app includes using alternative style sheets. This worked great on iOS 4 Safari and works fine on Safari on my desktop. However, I just upgraded one of our iPads to iOS 5 beta and it no longer works. Any ideas?

Here is my code for this.

function (options) {
    var i, a, main;
    for (i = 0; (a = document.getElementsByTagName("link")[i]); i++) {
        if (a.rel.indexOf("style") != -1
        && a.title) {
            a.disabled = true;
            if (a.title == options.title) {
                a.disabled = false;
                console.l开发者_高级运维og('The theme should be changing to : ' + a.title);                    
            }
        }

After searching SO and the web, I was not happy with any of the solutions. So I came up with a new solution which is working in chrome, ff, ie and safari and safari on an old ipad:

First set styles:

<link rel="stylesheet"              href="./codebase/touchui.css"       data-title="default"        type="text/css" media="screen" charset="utf-8">
<link rel="alternate stylesheet"    href="./codebase/ios.css"           data-title="ios"                type="text/css" media="screen" charset="utf-8">
<link rel="alternate stylesheet"    href="./codebase/jq.css"            data-title="jq"                 type="text/css" media="screen" charset="utf-8">
<link rel="alternate stylesheet"    href="./codebase/sky.css"           data-title="sky"                type="text/css" media="screen" charset="utf-8">
<link rel="alternate stylesheet"    href="./codebase/green.css"         data-title="green"          type="text/css" media="screen" charset="utf-8">

Notice the attribute "data-title" this is a user-defined attribute.

Then use this function to change the style sheet, (note that I have it set in the app scope, you can make it a standard function:

app = {}

app.styleSet=function(title) {
  var i, a
  var o;
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) 
    if (a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute('data-title') ) {
      if (a.getAttribute('data-title') == title) 
        o = a

      a.setAttribute("rel", "alternate stylesheet"); 
      a.setAttribute("title", a.getAttribute('data-title'));
      a.disabled = true
  }

  o.setAttribute("title", undefined); 
  o.setAttribute("rel", "stylesheet"); 
  o.disabled = false
  //app.cookieCreate("style", title, 365);
}