无法将ArrayList值绑定到GridView

Question

Array List值未绑定到Gridview，它总是返回消息：

  

名称为＆＃39; CUSTOMER_NAME＆＃39;的字段或媒体资源未在所选数据源中找到。

我有GridView作为

<asp:GridView ID="GdVClient" runat="server" 
    AllowPaging="True"
    CellPadding="4" 
    ForeColor="#333333" 
    GridLines="Vertical" 
    Style="width: 700px; height: auto;">
    <Columns>
        <asp:BoundField DataField="CUSTOMER_NAME" />
    </Columns>
</asp:GridView>

DisplayCustomer.aspx.cs：

protected void GetCustomer(object sender, EventArgs e)
{
     CutomerService cs    = new CutomerService();
     ArrayList alCustomer = cs.GetCustomerDetail();

     GdVClient.DataSource = alCustomer;
     GdVClient.DataBind();
}

CutomerService.cs：

[WebMethod(Description = "GetCustomerDetail1")]
public ArrayList GetCustomerDetail()
{
    DataSet dsCustomer = new DataSet();
    Hashtable htDetails = new Hashtable();
    ArrayList alDetails = new ArrayList();

    String sqlCustomer = "SELECT [CUSTOMER_NAME]FROM [SAMPLE].[dbo].  [CUSTOMER]";
    dsCustomer = SqlHelper.ExecuteDataset(SampleProjectConn.SPConn,     CommandType.Text, sqlCustomer);

    foreach(DataRow row in dsCustomer.Tables[0].Rows)
    {
        htDetails = new Hashtable();
        foreach(DataColumn col in dsCustomer.Tables[0].Columns)
        {
            htDetails.Add(Convert.ToString(col.ColumnName),  Convert.IsDBNull(row[col.ColumnName]) ? string.Empty : Convert.ToString(row[col.ColumnName]));
        }
        alDetails.Add(htDetails);
    }

    return alDetails;
}

如何将值绑定到GridView？请帮忙。谢谢。