Module development and code questions

Is it possible through a module or manually editiing certain files, to disable the ability of users to delete uploaded files?

I would like to know exactly which files were uploaded on my site, and if users can upload and delete them at will then I lose that ability.

can anybody tell me what's wrong with the following code?

the form's default value is not displaying although it works well when used as this: '#defaultvalue' => t('asdf')

<?php
function classes_form(){
$arg = arg(3);
if($arg == 'add'){
$form['classname'] = array(
'#type' => 'textfield',
'#required' => true,
'#title' => t('Text Number One'),
'#size' => 30,
'#maxlength' => 50,
'#weight' => -1,
);
$form['weight'] = array(
'#type' => 'textfield',
'#required' => true,
'#title' => t('Text Number Two'),
'#size' => 2,
'#maxlength' => 2,
'#weight' => -2,
);
}elseif($arg == 'edit'){
$classID = arg(4);
$result = db_query("SELECT className, weight FROM grades_classes WHERE classID = %s LIMIT 0,1", $classID);
$row_result = db_fetch_object($result);
$form['classname'] = array(
'#type' => 'textfield',
'#required' => true,
'#title' => t('Text Number One'),
'#size' => 30,
'#maxlength' => 50,
'#weight' => -1,
'#defaultvalue' => $row_result->className
);
$form['weight'] = array(
'#type' => 'textfield',
'#required' => true,
'#title' => t('Text Number Two'),
'#size' => 2,
'#maxlength' => 2,
'#weight' => -2,
'#defaultvalue' => $row_result->weight
);
}
return system_settings_form('classes_form', $form);

I've a problem with the the modules flexinode and front_page.
I've added a new flexinode -> node/flexinode-1 and the frontpage module. If I add a new article and the checkbox "promote to frontpage" is selected, the teaser of the article will shown on my flexinode-1 page.

Is it possible to change the default frontpage?

thx
dominik

I'm researching the option of using Drupal for our Flash sites and the AMFPHP module looks very promising. Problem is I have just started using Drupal so basically I'm looking for some examples to give me a headstart. One of the issues I ran into sofar:

How do I Lock a site while I need to do maintenance on it? Then how would I unlock it?

Jay

Helllo
Everybody
I want the toolbar on the create content page when user want to create new page or edit existing page if anyone have idea about that please tell.

thanks