<?php

    if(isset($_POST['submitForm'])) {
        $personWeight = $_POST['personWeight'];
        $personHeight = $_POST['personHeight'];

        if($personWeight > 300 | $personWeight < 20) {
            header('Location: index.php?error=weightError');
            die();
        } else if($personHeight > 3 || $personHeight < 1) {
            header('Location: index.php?error=heightError');
            die();
        }

        echo "Apskaičiuotas KMI: " . calculateKmi($personWeight, $personHeight);
    } else {
        header('Location: index.php');
        die();
    }

    function calculateKmi($personWeight, $personHeight) {
        return $personWeight / ($personHeight * $personHeight);
    }