>I assume that the code (referencing This.Buttons.(This.Value).Caption) is in the click event of the option button group, rather than an individual button. About the only thing that I can think of is that the value of the group isn't initialized or is somewhere set to 0.


You are right, the code is in the click event. But I am not sure whether the value of the group is initialized or not. Because if used with only a form, and the optiongroup buttons in it.And no tables in the buffermode etc. It can work.

Why?