Attempting to Limit User Password Length Through PHP Plugins

[Mko]

Hey all,
I'm trying to make it so user passwords need to be at least 6 to 20 characters long.
PHP Plugins:

register_addmember_process

PHP Code:

echo strlen($_POST['password']);
echo strlen($vbulletin->GPC['password']);

if (strlen($vbulletin->GPC['password']) < 6) {
    $userdata->error('test1');
} else if (strlen($vbulletin->GPC['password']) > 20) {
    $userdata->error('fieldmissing');
} 


profile_updatepassword_start

PHP Code:

echo strlen($_POST['newpassword']);
echo strlen($vbulletin->GPC['newpassword']);

if (strlen($vbulletin->GPC['newpassword']) < 6){
    eval(standard_error("Invalid Password. Your password must be at least 6 characters and no more than 20 characters in length.")); 
} else if (strlen($vbulletin->GPC['newpassword']) > 20) {
    eval(standard_error("12")); 
} 


Now for some reason, every time I execute a plugin, both of the echo statements echo out '0' because supposedly the field I'm calling has no length.

If anyone could help me out and explain what needs to be done to actually obtain the length of the password inputted in the textfield, I'd appreciate it!


Thanks,
Mark