Question

if(defined($_POST["message"]) && defined($_POST["name"]))
{

In that if block an exception is thrown constantly. I am looking for a function that will prevent this by testing if it the post variable exists..if it doesnt exists return false instead of throwing an exception

Answer 1

if (isset($_POST["message"]) && isset($_POST["name"])) {
    // ....
}

or if you want to check them to be not only set but also non-empty:

if (!empty($_POST["message"]) && !empty($_POST["name"])) {
    // ....
}