File upload

[eluser]ninjayan[/eluser]
I have a form which accepts user inputs and a file.
I am not using the CI upload class and want to use the core php in uploading.
My problem is when I check if the $_FILES is empty or not.
I'm not sure why $_FILES is ignored in CI. Please have a look

<code>
&lt;form acti echo base_url('documents/save_document'); ?&gt;" id="new_document_form" class="forms" method="post" enctype="multipart/form-data"&gt;
&lt;input type="file" name="attached_file" id="attached_file" accept="application/pdf" multiple&gt;
&lt;/form&gt;

----
controller
----
if (!empty($_FILES['attached_file']['tmp_name']))
{
$data['errors'] = 'a';
}
else
{
$data['errors'] = 'b';
}
</code>

Here is my jquery form submit code

<code>
$('#new_document_form').on('submit', function(){
var save_form = $(this);
alert(save_form.serialize();
return false;
});
</code>
input:file value not showing in alert

[eluser]thebigpj[/eluser]
&lt;form acti echo base_url(‘documents/save_document’); ?&gt;” id=“new_document_form” class=“forms” method=“post” enctype=“multipart/form-data”&gt;

Should that not be:
&lt;form acti echo base_url(‘documents/save_document’); ?&gt;”

?