Anonymous

<?php
$a1 = $_POST["a"];
$a2 = $_POST["a2"];
$a3 = $a1 + $a2;

if (!isset($a1) || !isset($a2)) {
die ("Fill in the boxes nubcake!");
}

elseif (!is_numeric($a1) || !is_numeric($a2)) {
die ("Numbers only!"); 
}

else {

print "The angle is <i>$a3</i>";

}

?>