function openWindow(href, innerW, innerH, f){
	if(f==null || f.closed){
		var fLeft, fTop;
		if(screen.width<800){
			fLeft = 0;
			fTop = 0;
		}else{
			fLeft = parseInt((screen.availWidth - innerW)/2);
			fTop = parseInt((screen.availHeight - innerH)/2);
		}
		f = window.open(href, "f2", "width=" + innerW + ",height=" + innerH + ",left=" + fLeft + ",top=" + fTop + ",location=no,menubar=no,status=no,resizable=no");
   	}else{
		f.location.href = href;
	}
	return f;
}