Uploading file and problem

Hello,

First, I'm a newbie in module developement so please be kind with me :)

I'm trying to develop a module for my personal use which allow any user to upload a file on my server (I know, a module exist for that but my module will do more than just uploading a file.

So, here is my code:

...
$form['#attributes'] = array('enctype' => "multipart/form-data");$form['file'] = array(
                '#type' => 'fieldset',
                '#title' => t('File'),
                '#collapsible' => TRUE, // Added
                '#collapsed' => FALSE,  // Added
                );
        $form['file']['content'] = array(
		'#type' => 'file',
		'#description' => "No more than 100KB.",
                '#title' => 'Filename',
		);

	$form['next'] = array(
		'#type' => 'submit',
		'#value' => 'Next',
		);

function ar_cards_my_form_validate($form, &$form_state) {
	$validators = array(
    		'file_validate_is_image' => array(),
    		'file_validate_size' => array(30 * 1024),
  	);
	
	$file=file_save_upload('content', $validators);
	if (!$file) {
		form_set_error('content','Error uploading file: too big or wrong file type');
		//image_get_info($file->filepath);
		//file_directory_path()
		//form_set_error('content',file_check_directory(file_directory_path()));
	}else{
		file_set_status($file, 1);
	}

function ar_cards_my_form_submit($form, &$form_state) {
                /*
                Normally, some code would go here to alter the database with the data
                collected from the form. Sets a message with drupal_set_message()
                to validate working code.
                */
                $image_path = $form_state['values']['content'];

                drupal_set_message(t('The form has been submitted.'));
                drupal_set_message(t('Value: '.$image_path));
                unset ($form_state['storage']); // This value must be unset for
                // redirection! This is because
                // $form_state['rebuild'] gets set to TRUE
                // when 'storage' is set. See code sample
                // #9 for more on this.

                $form_state['redirect'] = 'ar_cards/upload'; // Redirects the user.
        }

But it seems that I can upload a file which is 500k event if, I think, I said in the code that it cannot be bigger than 30k

Can someone explain it to me?