How do I refresh a DIV content?

<div id='here'></div>

I am trying to refresh a certain div within a bunch of divs. The div content is basically generated by PHP along with data from a MySQL database in addition to many variables being sent with the help of an XMLHttpRequest.

The idea is to reload/refresh the div itself and not load a php file or to overwrite it with .text or .html. In this case, I cannot use .load('file.php')

What I have tried :

<script type='text/javascript'>
    function updateDiv()
    { 
        document.getElementById("here").innerHTML = document.getElementById("here").innerHTML ;
    } 
</script>

and (for a every 3 second refresh) :

$(document).ready(function () {
    setInterval(function () {
        $('#here').load('#here'));
    }, 3000);
});

Ideally, I would require something like :

function reloadDIV () {document.getElementById("here").innerHTML.reload}

function reloadDIV () {$('#here').load(self)} 

so that I can use it in a onClick :

<a onclick='reloadDIV ();'>reload div</a>