clickmac on "[Plugin: WooCommerce - excelling eCommerce] remove billing address(css ) and email field using checkbox"

perhaps their is a add_action or add_filter to register that
"woocommerce_checkout_fields"

globally....

or that my function named "function_hook" that is hooked onto wp_head

should have another action to that function?

or the add_filter( 'woocommerce_checkout_fields' , 'override_checkout_fields' );

cannot be inside of another function....since in this case it is inside of the function_hook
and if it is in that case that
add_filter( 'woocommerce_checkout_fields' , 'override_checkout_fields' );
cannot be inside of another function example function_hook

how do i retrieve my saved values in the options.php file that was posted from the <form> so that i can use it in the

IF statement
example

<?php
if ( $my_checkbox  == '1' ) {
echo '<style type="text/css">
#customer_details {
display:none;
}
</style>';