checkbox syntax?

[kev@num]

hello, i've added a new filed in the "product" table called products_genre_nr and i've added a checkbox to categories.php which appears when i'm editing or adding a new product..

 

anyway, when i tick the box and click update, the db field is updated with the word "On" and when i uncheck it and press update the field looks blank (i'm not sure if it actually is though).

 

using the following code, it always shows a "Tick" regardless of what the field holds.. or am i submitting NULL wrong?

 

 

<?php 
echo tep_draw_separator('pixel_trans.gif', '24', '15') . ' ' .

tep_draw_checkbox_field('products_genre_nr', (isset($pInfo->products_genre_nr)) ? On : NULL);


?>

 

any help would be much appreciated!!

kev.

:)