<?php
function check_input($data, $err="")
{
    $data = trim($data);
    $data = stripslashes($data);
    $data = htmlspecialchars($data);
    if ($err && strlen($data) == 0)
        returnerr($err);
    return $data;
}

function returnerr($teherror)
    {
        echo $teherror;
        exit();
    }

if (isset($_POST["charname"])) {
    check_input($_POST["charname"], "All fields required, ffs.");
    //echo "Your character's name is " . $_POST["charname"];
}
if (isset($_POST["class"])) {
    check_input($_POST["class"], "Hey, pick a class!");
    //echo "Your character's class is " . $_POST["class"];
}
?>