CCK rating module

Hi,

Help me...

I am using Drupal 6.6.

I have created a CCK dependent module for star rating system with page type content. I have validate the input between 0 to 5 float numbers. This module is working very fine if I use integer type value in input, but I want to show half star as a rating with input value ".5", "1.5" and upto 5. In this module, the float type value is not going in database. I have used

case 'database columns':
if ($field['type'] == 'stars') {
return array(
'value' => array('type' => 'float', 'not null' => FALSE, 'sortable' => TRUE),
'format' => array('type' => 'float', 'length' => 2,2, 'unsigned' => TRUE, 'not null' => TRUE, 'default' => 0),
);
}

in module_fields_settings function to define the field type.

Please guide me for best solution, or please give me some code for direction.

Thanks in advanced.
Anurag