Warnings in admin mode

Please correct the following lines in your class-product-add-to-cart.php file:
line 41:
if(isset($_POST[‘submit’])) {
$checkco = (isset($_POST[‘checkco’]) ? ‘1’ : ‘0’);
$showot = (isset($_POST[‘showot’]) ? ‘1’ : ‘0’);
$showft = (isset($_POST[‘showft’]) ? ‘1’ : ‘0’);

line 66:
$tab = (isset($_GET[‘tab’]) ? $_GET[‘tab’] : ‘general’);

The indexes on every variable are not set the first time you enter the plugin admin page.

https://www.ads-software.com/plugins/woocommerce-custom-options-lite/