function openwin (url, target, w, h, s) {
	var widthscreen=800;
	var heightscreen=600;
	var top=0;
	var left=0;
	widthscreens=screen.availWidth;
	heightscreen=screen.availHeight;
	top=(heightscreen/2)-(h/2);
	left=(widthscreens/2)-(w/2);
	eval("window.open(url, target, 'top="+top+",left="+left+",menubar=no,directories=no,location=no,resizable='+s+',scrollbars='+s+',width='+w+',height='+h);");
}