var OpenWin=null

function openCWin( url,title,w,h ) {
 if (OpenWin!=null)
 {
	 if (!OpenWin.closed)
		OpenWin.close();
 }
 var ll=(window.screen.width-w)/2;
 var tt=(window.screen.height-h)/2;
 OpenWin = window.open(url, title,'top='+tt+',left='+ll+',width='+w+',height='+h+',toolbar=0,title=0,location=0,directories=0,status=0,menuBar=0,scrollBars=0,resizable=1');
}