I have a comments fields in the customers table (internally) and would like to make it a text_area not text_field when shown in admin/customers.php

Existing Code
PHP Code:
    <?php
  
if ($processed == true) {
    echo 
$cInfo->customers_comments zen_draw_hidden_field('customers_comments');
  } else {
    echo 
zen_draw_input_field('customers_comments'$cInfo->customers_occupationzen_set_field_length(TABLE_CUSTOMERS'customers_comments'15));
  }
?>
I believe the text_area shoule look something like this:
PHP Code:
<?php echo zen_draw_textarea_field('customer_comments'305''''''); ?>
But this doesn't seem to work. What am I missing?

How can I add a text_area to customer details in admin?

Thanks in advance