Gridview Cell Value And Array List

When I am tryng to pass the gridview cell values to an array everything is perfect but the array is empty after executing the code. When I see through debug mode the index of selected row also is fine, i.e. when I select two rows using checkbox among 1000 the count shows exactly 2 in the array but the data is empty. I'm not able to get the cell value from the gridview.

protected void Button2008_Click(object sender, EventArgs e)
{
ArrayList checkedItems = new ArrayList();
foreach (GridViewRow row in this.GridView1.Rows)
{
if (((CheckBox)row.FindControl("cbRows")).Checked == true)
{
checkedItems.Add(row.Cells[12].Text);
}
}
Session["CheckedItems"] = checkedItems;
Response.Redirect("About.aspx", true);
}