Something
public text v1 · immutable<HTML>
<HEAD>
<TITLE>Sandbox</TITLE>
</HEAD>
<BODY>
<?
if(isset($_POST['mybutton'])) {
echo "<p>Great! You clicked the button!</p>
</body>
</html>";
} else {
echo "<p>Click the button!</p>
<FORM method="POST" action="sandbox.php">
<INPUT type="submit" name="mybutton" value="Click me!">
</FORM>
</BODY>
</HTML>";
}
?>