I'm trying to change labels when pressing on a button on 2 different windowsForms.

If I open the second form I can change it easy but I cant figure out how to change data on a Form that's already open. I keep getting `NullRefferenceExecption`.

This is the code i use in my buttons on `Form1` and `Form2`:

```
public Form2 m_Form2;

m_Form2 = new Form2();
m_Form2.Show();
m_Form2.label1.Text = "pressed on form 1";

```

And:

```
public Form1 m_Form1;

m_Form1.label1.Text = "pressed on form 2";

```