Try this:
Text Formatted Code
<?php
global $_CONF;
$filename = '/var/www/html/internetsider/public_html/layout/CDCblues/images/logo.gif';
if (file_exists($filename)) {
print '<a href="'.$_CONF['site_url'].'/index.php"><img src="$filename" alt="'.$_CONF['site_name'].'"></a>';
} else {
print '<font size="6" color="#BEA982">'.$_CONF['site_name'].'</font>';
}
?>
If the above doesn't work, replace the print with echo. This should return the code to your browser. Reply back with what you see.
In a world without walls and fences, who needs Windows and Gates?