Since you are using a date drop down and using PHP will it not be easier if use a for loop? Also you can check if the $MyDate==$year option and set the selected='selected' statements. Check the code below.
echo "<option value='$year' $s>$year</option>";
Also note that in HTML what ivawafoo said is the correct syntax for the selection and in PHP you start of a PHP code with <?php not <php?.
You can test the above code by using the ?year=2006 URI.