Module install file not working properly

Hi All,

I'm a beginner of Drupal 6, and have been following the steps outlined in John K VanDyk's Drupal Pro Development 2nd Edn to get a hold of how to make Drupal modules.

So I just created the install file and now when i disabled and re-enabled the module, the new table is not being created. I've been trying to figure this out but am failing so I'm turning to the masses. Also when I try to uninstall (even though the install didnt happen, the variable delete function comes up as undefined)

<?php
function annotate_install() {
// Use schema API to create database table.
echo (drupal_install_schema('annotate'));
}

function annotate_uninstall() {
// Use schema API to delete database table.
drupal_uninstall_schema('annotate');
// Delete our module's variable from the variables table.
variable_delete('annotate_node_types');
}

function annotate_schema() {
$schema['annotations'] = array(
'description' => t('Stores node annotations that users write.'),
'fields' => array(
'nid' => array(
'type' => 'int',
'unsigned' => TRUE,
'not null' => TRUE,
'default' => 0,
'description' => t('The {node}.nid to which the annotation applies.'),
),
'uid' => array(
'type' => 'int',
'unsigned' => TRUE,
'not null' => TRUE,
'default' => 0,
'description' => t('The {user}.uid of the user who created the annotation.')
),
'note' => array(
'description' => t('The text of the annotation.'),
'type' => 'text',
'not null' => TRUE,
'size' => 'big'
),
'created' => array(
'description' => t('A Unix timestamp indicating when the annotation
was created.'),
'type' => 'int',
'not null' => TRUE,
'default' => 0
),
),
'primary key' => array(
'nid', 'uid'
),
);
return $schema;
}