Cross-Origin Request Blocked on

Question 1

This can be fixed by moving the resource to the same domain or enabling CORS

and the fact you are using WordPress, you can create a proxy very easy like this :

proxy.php :

<?
header('Content-type: application/json');
$url=$_GET['url'];
$json=file_get_contents($url);
echo $json;
?>

Then you want to call a resource outside the domain, as with AJAX, use proxy.php to fake that you are trying access the resource from the same domain. Like :

var url= "my-external-resource.com?param=value";
url = 'proxy.php?url='+url:
$.ajax({
    url: url,
    dataType: 'json',
    success:  function (data) {
        ...
    }
});

Here the result is expected to be JSON, but just change header / datatype to HTML, XML or whatever if needed.

Update : @Jason raises an interesting point about security. I totally agree. Under normal circumstances one could prevent remote access to files by .htaccess and a <Files> directive :

<Files proxy.php>
    Order Deny,Allow
    Deny from All
    Allow from 127.0.0.1
</Files>

...but this is not satisfactory, since it will prevent using proxy.php in AJAX calls as well. A solution is to check if proxy.php is called by another script :

if (!isset($_SERVER['HTTP_X_REQUESTED_WITH'])) {
    header('HTTP/1.0 403 Forbidden');
    die('You are not allowed to access this file.');     
}

This will allow using proxy.php in javascript AJAX calls, but prevent direct access from remote (or locally). See this answer for more about $_SERVER['HTTP_X_REQUESTED_WITH'] and XMLHttpRequest.

Question 2

$.ajax({
      type: 'POST',
      url: 'http://fscebook.comxa.com/index.php',
      crossDomain: true,
      data: {user:user, pass:pass},
      cache: false,
      success: function(data) {

        if($.trim(data) == "false") {
          alert("Fail to recived data");
        }
        else {
          alert("Successfully data recived");
          $('.results').html(data);
        }

      }
    });

Question 3

I had a similar issue using the glyphicons-haflings-regular.woff fonts that came with bootstrap ver3. After adjusting the css to place the font-family declaration before any and all tag declarations my problem went away

Question 4

Use headers for solve cross domain error:

 $.ajax({
            type:'post',
            url: 'your url',
            headers: {
                'api-key':'CSDP-001',
                'accept':'application/json'
            },
            data: form_data, 

            success:function(data){  
            }
       });

Question 5

We can fix the problem by placing base tag on our html.

<head>
<base href="http://www.otherdomain.com/xyz/">
</head>