shopping cart website

protected void checkoutBtn_Click(object sender, EventArgs e)
   {
       bool selected = false;


       StringBuilder ProductName = new StringBuilder();
       StringBuilder Quantity = new StringBuilder();
       string[] qua=null;
       // Select the checkboxes from the GridView control

       for (int i = 0; i < GridView1.Rows.Count; i++)
       {
           string[] name = new string[GridView1.Rows.Count];
           qua = new string[GridView1.Rows.Count];
           GridViewRow row = GridView1.Rows[i];
           bool isChecked = ((CheckBox)row.FindControl("ProductSelector")).Checked;

           if (isChecked)
           {
               // Column 0 is the name column

               ProductName.Append(GridView1.Rows[i].Cells[0].Text);
               Quantity.Append(((DropDownList)row.FindControl("DropDownList1")).SelectedItem.Value);
              // name[i] = GridView1.Rows[i].Cells[0].Text;
             //  qua[i] = ((DropDownList)row.FindControl("DropDownList1")).SelectedItem.Value;

           }

       }

       // prints out the result
       Response.Redirect("Basket.aspx?name=" + ProductName.ToString() + "&quantity=" + Quantity.ToString());


   }