Save variable Javascript in variable PHP

<script type="text/javascript">
function favoris(link) {

    var i=link.style.backgroundColor;

    if(i=="white") {

        link.style.backgroundColor = "red";
        var id=parseInt(link.name);
        console.log(id);



        <?php
            $id='<script type="text/javascript">document.write(id);</script>';
            var_dump($id);

            ?>
    }
</script>

I want to save a variable JavaScript in variable PHP ! it doesn t work. Help me please !!!