Demonstration of write/writeln functions and for/in loop

The JavaScript code:

var numlinks = 0; document.writeln('<table border="1">'); document.writeln('<tr><th>Property</th><th>Value</th></tr>'); for (var prop in document) { var value = document[prop]; if (value == "") value = " "; document.writeln('<tr><td>' + prop + '</td><td>' + value + '</td></tr>'); } document.writeln('</table>');