What is the property for field Script of C# FontDialog?

What is the property for this field? I've tried to use the font dialog for changing font of some text boxes in a Window Form project. But the font is not always be changed when I change this field.

I'm using Visual Studio 2013, .Net 4.7. The code is:

private void fontButton_Click(object sender, EventArgs e)
{
    if (fontDialog.ShowDialog() == DialogResult.OK) {
        textBox1.Font = fontDialog.Font;
    }
}