how to move the data from one gridview to another gridview

Question

when i press the button1 all the data in the gridview should move to another gridview in windows form application
here s my code pls correct it....

here i am getting only blank grid in    dataGridView2 

  private void button4_Click(object sender, EventArgs e)

        {

            foreach (DataGridViewColumn c in dataGridView1.Columns)

            {

                dataGridView2.Columns.Add(c.Clone() as DataGridViewColumn);

            }

        }