Sharing variables values between Dialog Boxes

[Deo12]

I really need an advice on this topic guys. I have 2 Dialog boxes. In the first dialog box I have combobox which I want to fill with the user's input. I want when the user types anything in the plane text in the second dialog box and presses [ADD], that "item" to be added to the combobox in the first dialog box.
I've tried this in the second dialog box:

CFirstDialog CFD;
CFD.Combobox.AddString(AddItemString);

But it gives an error when clicking ADD button. What's the simplest way to do it?

[coder777]

You need to add an event handler for the [ADD] button. Within this function you can copy the data.

[Deo12]

I've already done that. But it sitll gives me errors

[coder777]

So please show the code and what are the errors?