Option sanitize in wordpress theme panel ?

hi friends i have problem in my WordPress theme option admin panel but in textarea i try to post any html or script it automatic remove when i save it only text remain !

I found it in option-sanitize.php

function of_sanitize_textarea($input) {
global $allowedposttags;
$output = wp_kses($input, $allowedposttags);
return $output;
}
 
add_filter('of_sanitize_textarea', 'of_sanitize_textarea');

PHP:

After Searching lot i found

/*
* This is an example of how to override a default filter
* for 'textarea' sanitization and $allowedposttags + embed and script.
*/
add_action('admin_init','optionscheck_change_santi ziation', 100);
function optionscheck_change_santiziation() {
remove_filter( 'of_sanitize_textarea', 'of_sanitize_textarea' );
add_filter( 'of_sanitize_textarea', 'custom_sanitize_textarea' );
}
function custom_sanitize_textarea($input) {
global $allowedposttags;
$custom_allowedtags["script"] = array( "src" => array() );
$custom_allowedtags = array_merge($custom_allowedtags, $allowedposttags);
$output = wp_kses( $input, $custom_allowedtags);
return $output;
}

PHP:

it allow only script and src but still i want allow any kind in textarea can any body help ? Actually i want modify this script and allowed all kinds of code like html and script in my theme option textarea so any can modify script ?