 <p>Try to add method atribute for form, like</p> <pre><code>&lt;form action="'+url+'" method="post" target="_blank"&gt;&lt;/form&gt; </code></pre> <p><strong>UPDATED</strong> But you can't store data in your url. Post should send params in body, not in URL. So your url should be like '/index.php'. And your params should be in body, so add all your page, action, etc to form's hidden fields.</p> <pre><code>&lt;form action="/index.php" method="post" target=...&gt; &lt;input type="hidden" name="action" value="InvoicePrint"/&gt; ............ &lt;/form&gt; </code></pre> <p>or use jQuery post</p> <pre><code>$.ajax({ type: "POST", url: '/index.php', data: data, success: success }); </code></pre> <p>Where data is object with all your params</p>