Replace target='_top'
with target=_blank
.
That will open a new window.
If you want a more traditional popup (i.e. smaller, no navigation bar, etc.), you should use some code similar to this (from here)
<script type="text/javascript">
// Popup window code
function newPopup(url) {
popupWindow = window.open(
url,'popUpWindow','height=700,width=800,left=10,top=10,resizable=yes,scrollbars=yes,toolbar=yes,menubar=no,location=no,directories=no,status=yes')
}
</script>
<a href="JavaScript:newPopup('http://YOUR URL HERE');">Pin it!</a>