Add(horz.Horz().SizePos());
optree.SetRoot("Parent");

optree.Add(0,x[0],"a");
optree.Add(0,x[1],"b");
optree.Add(0,x[2],"c");
optree.Open(0);
		
//if i add below Callback function,the ParentOption`s checkstate //will lose
x[0] <<= THISBACK(OnOption1);

x[0] << THISBACK(OnOption1);