C# listView add element

A have problem with add element to my listView. I have Form1 with:

    private void button1_Click(object sender, EventArgs e)
    {

        DodajWindow Dodaj = new DodajWindow();
        Dodaj.Show();

        ListViewItem lvi = new ListViewItem(DodajWindow.s);
        listView1.Items.Add(lvi);
    }

And Form2 with:

    public static string s;

    public void button1_Click(object sender, EventArgs e)
    {
        s = textBox1.Text;
        this.Close();
    }

Ok, this code isn't work good, becouse added to my listView:

1 line: " "

2 line: "word"

Why added empty line?