function openWindow(url,width,height,scrollbars) {
	x = (640 - width)/2, y = (480 - height)/2;
	if(scrollbars==true){
		scrollbarsOption = 'yes';
	}else{
		scrollbarsOption = 'no';
	}
	if (screen) {
		y = (screen.availHeight - height)/2;
		x = (screen.availWidth - width)/2;
	}
	window. open(url,'newWin','width='+width+',height='+height+',screenX='+x+',screenY='+y+',top='+y+',left='+x+',scrollbars='+scrollbarsOption+'');
}