$_post does not work in I.E

I thought I understood the ‘POST’ concept when using PHP.
When I click on any photo in firefox, the appropriate values are echoed.
However, in IE, they do not.

Here is my scaled down code:

<?php print_r($_POST); ?>

<html><head></head><body>

<form name=“form1” method=“post” action="<? echo $PHP_SELF; ?>">

<input type=“image” src=“fd-03.jpg” name=“photo” value=“photo-1”>
<input type=“image” src=“fd-04.jpg” name=“photo” value=“photo-2”>
<input type=“image” src=“fd-05.jpg” name=“photo” value=“photo-3”>

</body></html>

The photos do not have to exist to get the same results.
Is it my code, or my version of I.E. (verison = 7.0.5730.11) or any other explaination?
Any and all help is appreciated. Thank you in advance.
Dan