Rails：通过ajax获取远程页面

I use Rails3 and I try to get remote page via ajax. (https://play.google.com/store/apps/details?id=).

$.ajax({
      url: app_url,
      type: 'GET',
      data: "id=<id>",
      crossDomain : true,
      dataType: 'jsonp',
      success: function ( code ) {
        alert("Good.");
      }
    });

When I run the script, the I see: "Uncaught SyntaxError: Unexpected token < " error message.

By the way, I tried do it as:

$.ajax({
      url: app_url,
      type: 'GET',
      data: "id=<id>",
      crossDomain : true,
      dataType: 'jsonp',
      success: function ( code ) {
        alert("Good.");
      }
    });

But I see "Origin http://example.com:3000 is not allowed by Access-Control-Allow-Origin." error message.

How can I fix the error and get the page ?

Thanks.

If you are trying to access remote pages via AJAX, that page may be blocking your request. The error message would suggest this: https://developer.mozilla.org/en-US/docs/HTTP_access_control

EDIT

For clarity, Access-Control-Allow-Origin is the server setting which "origins" are allowed to retrieve from it. You could possibly grab this page server-side, and depending on google's level of security, you may have to spoof a browser. PHP CURL comes to mind. You would then set up an ajax call to your server script, your server would go get the page for you, then return it to you ajax call.