open image in new popup window

<a href="javascript:void(0);" onclick="openwin('http://basantmallick.com/admin/popup.php?img=category-images/Medical-Equipment-On-Rent-Purchase.jpg', '530', '580')" class="linkgray fontbold"><strong>View Image</strong>
                  
     </a>

<script>
function openwin(file,Iwidth,Iheight) {
	var newWin1=window.open(file,'nWin2','x=0,y=0,toolbar=no,location=no,directories=no,status=no,scrollbars=yes,copyhistory=no,width='+Iwidth+',height='+Iheight+',screenX=0,screenY=0,left=20,top=20');
}

</script>