function openwinOnCentre(url, w, h){
	window.open(url,'_blank','top='+(window.screen.height-h)/2+',left='+(window.screen.width-w)/2+',height='+h+',width='+w+',status = no,toolbar = no,scrollbars = no,titlebar=no,directories=no,resizable=no menubar=no,location=no');
	return;
}