Untitled

<html>
<head>
<?
$radius=$hoehe=$was="";
function volumen($r,$h)
{
  $vol=(3.141592*$r*$r*$h)/(3);
  return $vol;
}

function oberflaeche($r,$h,&$ober)
{
  $ober=(3.141592*$r*$r)+(3.141592*$r*$h);
}

if (isset($_POST["r"]) && isset($_POST["h"]) && isset($_POST["was"]))
{
  $r=$_POST["r"];
  $h=$_POST["h"];
  $was=$_POST["was"];


  if ($was =="V" || $was == "v")
  {
  $vol = volumen($r,$h);
  echo "Das Volumen des geraden Kreiskegels betr&auml;gt $vol mm<sup>3</sup>.";
  }
  else if ($was== "O" || $was == "o")
  {
  oberflaeche($r,$h,$ober);
  echo "Die Oberfl&auml;che des geraden Kreisgekels betr&auml;gt $ober mm<sup>2</sup>.";
  }
  else
  echo "Keine g&uuml;ltige Berechnungsart gew&auml;hlt.";
}
?>
</head>
<body>

<h2>Oberfl&auml;che und Volumen <br>des geradem Kreiskegels</h2>
<form action="./sb.php" method="post">
<table border="1">
<tr><td>Radius [mm]:</td><td><input type="text" name="r" size="3"
value="<?=$radius?>"></td></tr>
<tr><td>H&ouml;he [mm]:</td><td><input type="text" name="h" size="3"
value="<?=$hoehe?>"></td></tr>
<tr><td>O/V:</td><td><input type="text" name="was" size="3"
value="<?=$was?>"></td></tr>
<tr><td align="right" colspan="2"><input type="submit" name="knopf" value="Berechnung"></tr></table>
</form>

</body>
</html>