how to set accept in cell(2) after selecting in gridview

i have to set status as accept,reject for customer,while registering status while be pending. i need ,if condition for this, which row is selected then corressponding event should change in database as accept or reject

protected void Button2_Click(object sender, EventArgs e) {

SqlCommand cmd = new SqlCommand("select * from Testing", OIMS_01);

SqlDataAdapter ad = new SqlDataAdapter(cmd);

DataSet ds = new DataSet();

ad.Fill(ds);

if (GridView1.SelectedRow != null)

{

ds.Tables(0).Rows(0).Item(0) = GridView1.SelectedRow.Cells(1).Text;

ds.Tables(0).Rows(0).Item(1) = GridView1.SelectedRow.Cells(2).Text;

ds.Tables(0).Rows(0).Item(2) = "Accept";

}

else

{

ClientScript.RegisterStartupScript(this.GetType(), "alert", "alert('Please select a row.')", true);

}

ad.Update(ds);

}