'string' does not contain a definition for 'Checked'

protected void Button1_Click(object sender, EventArgs e)
    {
        foreach (GridViewRow row in GridView1.Rows)
        {
            string chk = (row.FindControl("chkdelete") as CheckBox).Text;

            if (chk.Checked)
            {
                string lblid = (row.FindControl("lblid") as Label).Text;

                SqlCommand comm =new SqlCommand();
                comm.CommandText = "delete from tbluser where id=@id";
                comm.Connection = conn;

                comm.Parameters.AddWithValue("@id",int.Parse(lblid.ToString()));


                conn.Open();

                comm.ExecuteNonQuery();

                conn.Close();
            }

            }

            LoadGridView();


        }

Error   1   'string' does not contain a definition for 'Checked'    C:\Documents and Settings\Harry\My Documents\Visual Studio 2005\deleting data from grid view\Default.aspx.cs    39  21  C:\...\deleting data from grid view\