I would just like my CSS Style to read a variable from Javascript and set the CSS "top" value accordingly. Example:
$topPosition = false;
?>
<script language='JavaScript' type='text/javascript'>
    function windowsHeightPixels() {
        windowsHeight = $(window).height()
        if (windowsHeight > 750) {
           topPosition = false;
           //set the $topPosition = false;
        }
        else {
            topPosition = true;
            //set the $topPosition = true;            
        }
    }
    windowsHeightPixels();
    alert ("Height is " + windowsHeight + " Top Position is " + topPosition); 
</script>
<style>
...
#fixedbutton {
    position: fixed;
    <?php if ($topPosition === false) : ?> top: 650px;
    <?php else : ?> top: 127px;</p>
    <?php endif; ?>
    ...
}
</style>
 
    