Issue with ajax login
<p>I have a ajax login system on a website. username and password submitting using post method. but randomly username and password showing in URL with a query string like <a href="http://www.example.com?username=abc&amp;pass=123456" rel="nofollow noreferrer">http://www.example.com?username=abc&amp;pass=123456</a>. 
why this is happening ? below is the code</p>

<pre><code>$(document).ready(function() {
    var $body = $('body'),
        $content = $('#content'),
        $form = $content.find('#loginform'); 
        $("input .logingform").uniform(); 
        $form.wl_Form({
            status:false,
            onBeforeSubmit: function(data){
                $form.wl_Form('set','sent',false);
                if(data.username || data.password){
                    $.ajax({
                        type: "POST",
                        url: $form.attr('action'),
                        data: 'username=' + data.username + '&amp;password=' + data.password + '&amp;rememberme=' + data.rememberme + '',
                        success: function(msg) {

                        }
                    });
                }else{
                    $.wl_Alert('Please provide something!','info','#content');
                }
                return false;

            }                             
        }); 
});
</code></pre>