function show(x, y) {
  document.write('<tr><td>' + x + '<td>' + y + '<td>' + (x == y ? 'Same' : 'Different'));
}

document.write('<table border>');
document.write('<tr><td>X<td>Y<td>X == Y');

show('abc', 'abc');
show('xyz', new String('xyz'));

document.write('</table>');