title: html form target _blank browser not allowed
body: <p>I need to send a post request to paypal, but before sending the form I need to verify some inputs and the paypal page must be opened in a new tab or window (doesn't matter). I can't send the request in the same window because in the main page I have background ajax callbacks. So the ideea is can I send the request in a new window or tab?</p>
  
  <p>In all major browesers this isn't allowed, browser keep blocking the request.</p>
  
  <pre><code>&lt;form action="https://www.paypal.com/cgi-bin/webscr" method="post" target="_blank" id="paypal_form"&gt;
  &lt;input type='hidden' name='some_value' id='some_value' value='151' /&gt;
  &lt;/form&gt;
  
  &lt;div id='button_submit' onClick="verify_paypal_form();"&gt;SUBMIT !&lt;/div&gt;
  </code></pre>
  
  <p>And now the ajax part:</p>
  
  <pre><code>function verify_paypal_form(){
     $.post('verify.php', { someValue : 'FOO' },
     function(data){
        if( data == 'OKAY' ) $('#paypal_form').submit();
     });
  }
  </code></pre>