I'm trying to add some text to a listBox in a form, from another form, but I get red underlines in the code that should add to the listBox. Isn't it possible to pass data to a form in a class from another class that I'm trying to do? I'm using VisualStudio 2013

I have this code I'm using in the MainForm class:

```
    // Local object of SearchResultForm
    SearchResultForm frmSearchResult = new SearchResultForm();
    frmSearchResult.Show();
    frmSearchResult.listBox.IsEnabled == false;

```

Error message: inaccessible due to its protected level