приведение типов???

[nikozavr]

Помогите исправить ошибку в коде:

namespace megasreda
{
    public partial class Form21 : Form
    {
        public Form21()
        {
            InitializeComponent();
        }

        private void button5_Click(object sender, EventArgs e)
        {
            double a_Form21, b_Form21, x_min_Form21, x_max_Form21;
            a_Form21 = Convert.ToDouble(textBox1.Text);
            b_Form21 = Convert.ToDouble(textBox2.Text);
            x_min_Form21 = Convert.ToDouble(textBox3.Text);
            x_max_Form21 = Convert.ToDouble(textBox4.Text);

            Form22 myForm22 = new Form22();
            myForm22.a = a_Form21;
           myForm22.b = b_Form21;
            myForm22.x_min = x_min_Form21;
            myForm22.x_max = x_max_Form21;


        }
    }
}

[nikozavr]

Понял:
(float)