$_FILES is empty when working with wordpress custom field image uploading but, its working in core php website

Question

<form enctype="multipart/form-data" method="post" action="uploader.php">
        <input type="file" name="pic" /><br />
        <input type="submit" value="Upload File" />
    </form>

$file_title = $_FILES["pic"]["name"];
echo "$file_title";

in wordpress functions.php file; custom field methos are:

function credits_meta() {
  global $post;

 $custom = get_post_custom($post->ID);
 $designers = $custom["designers"][0];
 $developers = $custom["developers"][0];
 $producers = $custom["producers"][0];
 ?>

<form method="POST" enctype="multipart/form-data">
 <p><label>Designed By:</label><br />
 <textarea cols="50" rows="5" name="designers"><?php echo $designers; ?></textarea></p>
 <p><label>Built By:</label><br />
 <textarea cols="50" rows="5" name="developers"><?php echo $developers;  ?> </textarea></p>
 <p><label>Upload Image :</label><br />
 <input type="file" name="myPhoto" size="25"/></p>
 </form>

  <?php
  }
function save_details(){
 global $post;

 $target_path = get_bloginfo('template_directory')."/images/";
 $file_title = $_FILES["myPhoto"]["name"];

$new_file_title = "wp_".$file_title;

update_post_meta($post->ID, "year_completed", $_POST["year_completed"]);
update_post_meta($post->ID, "designers", $_POST["designers"]);
update_post_meta($post->ID, "developers", $_POST["developers"]);
update_post_meta($post->ID, "producers", $new_file_title);
}

when i try the above code with core php it works fine but, when i try to do the same in wordpress custom fields image uploading: $_FILES alwasy gives empty.

it gives the name of the image if i use $_POST["pic"];

I have tried to check this with print_r, var_dumb and even in wordpress functions.php file with this:

  add_action('init', 'myfunction');
  function myfunction(){
    if($_FILES){

      die("something");
    }
  }

still it gives empty. the file size which i'm trying to upload is 153kb.

My php.ini file:

file_uploads = on;
upload_max_filesize = 2M

Any help would be appreciated

Answer 1

Adding the following hook in the functions.php file solves the problem.

add_action( 'post_edit_form_tag' , 'post_edit_form_tag' );

function post_edit_form_tag( ) {
   echo ' enctype="multipart/form-data"';
}

Answer 2

remove action

<form enctype="multipart/form-data" method="post" action="">