language file name can't retrieved from database... need help..

I am wondering if anyone out there can help with my language SCRIPT Please?

<?php

function select_lang(){
echo '<select name="SITE_LANG" id="select8">';

$lang = opendir("../lang");
    while($longFileName = readdir($lang)) {
        if ($longFileName[0] != "." && $longFileName[0] != ".." ) {
        $shortFileName = str_replace(array('', '.php'), '', $longFileName);
		?>
                <option value="<?php echo $shortFileName;?>" <?php echo ($SITE_LANG == $shortFileName) ? 'selected="selected"' : ''; ?>><?php echo $shortFileName;?></option>
		<?php
        $count++;
        }
    }
    echo '</select>';
closedir($lang);
}
?>
          <tr>
            <td ><b>Site Languange</b></td>
            <td>
              <?php select_lang(); ?>
            </td>
          </tr>

PHP:

the problem is the <?php echo ($SITE_LANG == $shortFileName) ? 'selected="selected"' : ''; ?> can't retrieved from mysql database as matched with files in the directory and then showing as selected language...