Hello,
This error appears because of your PHP error reporting settings. Usually, it appears when your variable is not properly set. There are two ways to handle this issue:
1. Check if $_POST is set before using it. For example:
if (!isset($_POST['action']))
{
//If not isset -> set with dumy value
$_POST['action'] = "undefine";
}
2. Suppress Notice warnings
Notice warnings could be suppressed by changing the error_reporting variable in your PHP.ini. error_reporting could be set to show all errors except those for notices and coding standards warnings: error_reporting = E_ALL & ~E_NOTICE
The same is accomplished by adding the following line in your php page:
<?php error_reporting (E_ALL ^ E_NOTICE); ?>
You could also change the error reporting value in your php.ini
or use the following in the .htaccess file (if your server allows that):
Code:php_flag display_errors on
php_value error_reporting 6135