stop the_permalink printing and save as variable?

Is there a way i can get the_permalink as a variable? I need to build an info window with it but it wont appear in the $infoWindow variable…

<?
    $link = the_permalink($post->ID); // prints out into html
    $infoWindow = '<div><h2><a href="'.$link.'">'.$post->post_title.'</a></h2></div>';
?>
<script type="text/javascript">
    marker = [<?=$v_latitude?>, <?=$v_longitude?>,"",'<?=$infoWindow?>'];
    locations.push(marker);
</script>   

best, Dc