Now I've tried Don's code and tweak it a little more like this:
<?php
function the_user_level () {
if (is_user_logged_in()) {
global $current_user, $wpdb;
$userLevel = $wpdb->get_var("SELECT meta_value FROM $wpdb->usermeta WHERE user_id=$current_user->id AND meta_key='wp_user_level'");
return $userLevel;
} else {
return 0;
}
}
?>
<?php
$accessLevel = the_user_level();
if ($accessLevel < 8) {
add_action( 'admin_footer', 'catlist2radio' );
function catlist2radio(){
echo '<script type="text/javascript">';
echo 'jQuery("#categorychecklist input, #categorychecklist-pop input, .cat-checklist input")';
echo '.each(function(){this.type="radio"});</script>';
}
}else {
echo '';
}
?>
The idea is, I want all user with level less then 8 (editor - subscriber) have to choose category with radio button, while admin still allowed to pick more then 1 cats per post with checkboxes.
The problem is, it works well with FF, Opera, & Safari but in IE, checkbox appeared again.
Please help