I am really just beginning to understand PHP so bare beside me here. I am creating a theme options page and that i have CSS3 Cake and i wish to have the ability to allow the user disable it having a check box but it's not crippling it, I am sure i am carrying out incorrectly. This is exactly what i've:

<?php   // Rounded corners - CSS3-PIE for Internet Explorer
if ( isset ($options['sonar_disable_ie_css3'])&&  ($options['sonar_diable_ie_css3']!="")) echo ('');
else { ?>
<!--[if lte IE 8]>
<style type="text/css" media="screen">
#site-wrap , #colophon, #content, #social-widget, #primary, #secondary, h3.widget-title,
.calendar, .calendar > .month , .calendar > .day, .comments-link-top a
{behavior: url(<?php echo get_template_directory_uri(); ?>/js/ie-pie/PIE.php); position:relative; }
</style>
<![endif]--> 
<?php }

Thanks ahead of time.