files not uploading in codeigniter - php

Question

I am trying to upload 2 files through a codeigniter controller. When i select the files and hit submit it always returns error. But when i do a var_dump($_FILES); it shows that the files are passing but not being captured by the codeigniter controller.
Can someone tell me what i am doing wrong? Below is my code
$config['upload_path'] = './docs/';
$config['allowed_types'] = 'jpg|doc|docx';
$config['max_size'] = 10000;
$config['max_width'] = 3000;
$config['max_height'] = 3000;
$this->load->library('upload', $config);
if ( !$this->upload->do_upload('userfile1') || !$this->upload->do_upload('userfile2'))
{
echo "error";
} else {
$f1= $this->upload->data('userfile1');
$f2= $this->upload->data('userfile2');
echo $f1['file_name'];
echo $f2['file_name'];
}

Answer 1

For multiple file uploading in CI please follow this way --
$config['upload_path'] = 'uploads/photos/';
$config['allowed_types'] = 'jpg|jpeg|png|gif';
$this->load->library('upload', $config);
for ($i=0; $i < count($_FILES['photos']['name']); $i++) {
$_FILES['photos[]']['name'] = $_FILES['photos']['name'][$i];
$_FILES['photos[]']['type'] = $_FILES['photos']['type'][$i];
$_FILES['photos[]']['tmp_name'] = $_FILES['photos']['tmp_name'][$i];
$_FILES['photos[]']['error'] = $_FILES['photos']['error'][$i];
$_FILES['photos[]']['size'] = $_FILES['photos']['size'][$i];
if ($this->upload->do_upload('photos[]')) {
$photos_files = array('upload_data' => $this->upload->data());
$photos_arr[] = $photos_files['upload_data']['file_name'];
}else{
$error[] = $this->upload->display_errors();
}
}