how to take the data in back hand form in c# .net

ok i can paste

i use its code in long project ..so to create it in other small project thann i send u

public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
textBox1.Text = Class1.mystring;
}

private void button1_Click(object sender, EventArgs e)
{
Form2 f2 = new Form2();
f2.Show();


}
}
public partial class Form2 : Form
{
public Form2()
{
InitializeComponent();
}

private void button2_Click(object sender, EventArgs e)
{
Form1 f1 = new Form1();
f1.mdiparent=this;
this.Close();
f1.Show();
Class1.mystring = textBox2.Text;
}