can any one help me with this script I am just gettin started with PHP
I am trying to create an calculation script that would
calculate the
Constant: PI = 3.1415926535
Radius, area, and circumference of a circle .
This is what I have dont so far but just cant seem to get it working
can some one tell me what i am doing wrong
<html>
<head>
<title>
Calculation Form
</title>
</head>
<body>
<form method="post" action="circumference.php">
<p>Rad:<input type="text" name="radius=" size=10></p>
<p><input type="submit" name="submit" value="calculate"></p>
</form>
</body>
</html>
PHP Script
<? php
if (!isset($_POST['submit'])) {
echo '<form action="' . $_SERVER['PHP_SELF'] . '" . method="post">' .
'<input type="text" name="radius" />' .
'<input type="submit" name="submit" value="Calculate" />' .
'</form>';
} else {
$circumference = M_PI * $_POST['radius'] * 2;
$area = M_PI * pow($_POST['radius'], 2);
echo 'Circumference = ' . $circumference . ' units<br />';
echo 'Area = ' . $area . ' sq. units<br />';
}
?>
<html>
<head>
<title></title>
</head>
<body>
<p> This result of the is : <? echo "$result" ; ?></p>
</body>
</html>
Thanks
Unsolved 
