Say I have a list called `listOfFruits` in my main form. In a second form I've made I want the user to be able to remove items from that list to a second list called `removedFruits`. Currently I know I can access these lists in my second form simply passing them as parameters in the form constructor. However c# can't do pointers (correct?) so how can I effect the main form's copy of these lists from my second form? Because currently any changes to those lists in my second form don't effect the main form's original copy of the lists. If I were to remove 5 fruits from the `listOfFruits` passed to my second form then after finishing my work the main form would still still have a full `listOfFruits` and an empty `removedFruits`. Is there a simple fix to this? Maybe a get/set or a way to add/remove items from the original lists from the second form? Maybe the answer is in some sort of accessor stuff?

EDIT: To clarify; I want to add to one list, and remove from another. Not add/remove to the same list. Not sure if this matters entirely but I figured I'd be specific here in case it does.

EDIT2: I think the issue is I'm copying the original list from the first form and not editing it directly. Can someone fix my code so I can access the original list from my second form instead of making a copy of the list?

```
public partial class ListSelector : Form
    {
        private string windowName = Form1.typeOfModuleAdded;
        public List<IOModule> innerIOList;
        IOModule cardAdded = null;

        public ListSelector(List<IOModule> cardList)
        {
            this.Text = windowName;
            innerIOList = cardList;
            InitializeComponent();
            InitializeList();
        }
    private void InitializeList()
    {
        if (windowName == "Drive")
        {
            string[] listDrives = { "ACS880", "test" };
            listBox1.Items.AddRange(listDrives);
        }

        else if (windowName == "IOBlock")
        {
            if (!innerIOList.Any())
            {
                MessageBox.Show("No cards loaded! Please import cards from IO List.", "Error Empty Data", MessageBoxButtons.OK, MessageBoxIcon.Error);
                this.Close();
            }
            foreach (IOModule card in innerIOList)
            {
                cardAdded = card;
                listBox1.Items.Add(card.name);
            }
        }
        else if (windowName == "Local Card")
        {
            string[] listLocals = { "1756-EN2T", "test" };
            listBox1.Items.AddRange(listLocals);
        }
        else if (windowName == "Processor")
        {
            string[] listProcessors = { "1756-L71S", "test" };
            listBox1.Items.AddRange(listProcessors);
        }
    }

    private void addBtn_Click(object sender, EventArgs e)
    {
        if (listBox1.SelectedItem != null)
        {
            Form1.SetModule(listBox1.SelectedItem.ToString());
            Form1.confirmedAdd = true; 
            this.Close();
        }
        else if (cardAdded != null)
        {
            innerIOList.Remove(cardAdded);
        }
        else
        {
            MessageBox.Show("No module selected!");
        }
    }

```

and here's how I pass the list to that form from my first form:

```
        ListSelector test = new ListSelector(ioList);
        test.ShowDialog();

```

where ListSelector is the name of my second form, and ioList is the list im passing to it.

EDIT3: added more code