File Upload

gistfile1.txt

  $file = file_save_upload('bg_upload');
  if ($form_state['values']['bgon'] == 1) {
    if ($file) {
	    $parts = pathinfo($file->filename);
	    $destination = 'public://' . $parts['basename'];
	    $file->status = FILE_STATUS_PERMANENT;
	   
	    if(file_copy($file, $destination, FILE_EXISTS_REPLACE)) {
	      $_POST['bg_path'] = $form_state['values']['bg_path'] = $destination;
	      // If new file has a different name than the old one, delete the old
	      if ($destination != $previous) {
	        drupal_unlink($previous);
	      }
	    }
	  } else {
	    // Avoid error when the form is submitted without specifying a new image
	    $_POST['bg_path'] = $form_state['values']['bg_path'] = $previous;
	  }
  }
  else {
	  $_POST['bg_path'] = $form_state['values']['bg_path'] = '';
  }