function showpop(page, pagewidth, pageheight){
	var p = page;
	var w = pagewidth;
	var h = pageheight;
	var x = (screen.width - w) / 2;
	var y = (screen.height - h) / 2;

	window.open(''+p+'','','width='+w+',height='+h+',toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=no,left='+x+',top='+y+'');
}

//<a href="javascript:showpop('page.html', '800', '600');">Link</a>