Autoscroll full size including the non-visble area

Question

Hi,  sorry i don´t speak english very good but i`ll try to explain my problem. I have a Panel with the Autoscroll property set to true, I add another panel inside the first one and the scrollbars appear, i want to know the new Full size (including the part that i need to scroll to see) of the first panel. I have tried to print many properties of the panel before and after i add the second panel inside it, and none of them changes (Bounds,Size,ClientSize,ClientRectangle). I`ll really appriciate your help thank you.