the basic switch program is not working NEED HELP ASAP

    <script type="text/javascript">
    var a = prompt("enter day")
</script>
<?php
echo "<h1> YOUR DIET CHART</h1><BR><HR>";
$abc="<script>document.write(a)</script>";
echo "$abc";
    $c=settype($abc, "STRING");
    echo $c;
$b=strtoupper($c);
echo $b;
switch ($b) {
    case "MONDAY":
        echo "<br><br><h1>green veggies</h1>";
        break;

    case "TUESDAY":
        echo "<br><br><h1>green FRUITS</h1>";
        break;

    case "WEDNESDAY":
        echo "<br><br><h1>EGGS</h1>";
        break;

    case "THURSDAY":
        echo "<br><br><h1>CARROTS</h1>";
        break;

    case "FRIDAY":
        echo "<br><br><h1>EAT ANYTHING</h1>";
        break;

    case "SATURDAY":
        echo "<br><br><h1> TOMATOES</h1>";
        break;

    case "SUNDAY":
        echo "<br><br><h1>WHEAT BASED</h1>";
        break;
    default:
        echo("ENTER A VALID DAY,BRUH!");

}
?>

hii the code is not working ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,so;laeibjgnlbfjanvksnkjfvnksbnfvlkjfbvlbvkbffvlbdvfljbvjbakfjbvnajbnvajdbn;adjnfbv;jdnfbjndfjbndfnbvjadbfvjhbdfvhjbadfbvhajhbdfvjmcnb vhncdfjbvhb fcvhjb fvhb fhvb fyuewurghiewurhiuhdfkjsdhs c , , , ,, , , , , ,,

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