怎么让datagrid自动生成序列号？

代码实现：前台（WebForm1.aspx）：<asp:DataGrid id="grdCustomer" style="Z-INDEX: 102; LEFT: 30px; POSITION: absolute; TOP: 152px" runat="server" BorderColor="#CCCCCC" BorderStyle="None" BorderWidth="1px" BackColor="White" CellPadding="3" Font-Size="X-Small" AutoGenerateColumns="False"><SelectedItemStyle Font-Bold="True" ForeColor="White" BackColor="#669999"></SelectedItemStyle><AlternatingItemStyle BackColor="#FFF2F2"></AlternatingItemStyle><ItemStyle ForeColor="#000066" BackColor="#FAFFF9"></ItemStyle><HeaderStyle Font-Bold="True" ForeColor="White" BackColor="#006699"></HeaderStyle><FooterStyle ForeColor="#000066" BackColor="White"></FooterStyle><Columns><asp:TemplateColumn HeaderText="序号"><ItemTemplate><asp:label id="lable1" runat=server><%#GetCount()%></asp:label> </ItemTemplate></asp:TemplateColumn><asp:BoundColumn DataField="CustomerID" HeaderText="客户ID"></asp:BoundColumn><asp:BoundColumn DataField="CompanyName" HeaderText="公司名称"></asp:BoundColumn><asp:BoundColumn DataField="City" HeaderText="城市"></asp:BoundColumn><asp:BoundColumn DataField="Address" HeaderText="地址"></asp:BoundColumn></Columns></asp:DataGrid>
 
 
后台（WebForm1.aspx.cs）：int count;private void Page_Load(object sender, System.EventArgs e){     if(!IsPostBack)     {SqlConnection cnn = new SqlConnection();cnn.ConnectionString = "data source=localhost;initial catalog=Northwind;password=;"         +"persist security info=True;user id=sa;workstation id=APJ062;packet size=4096";          string sqlstr = "select Top 10 CustomerID, CompanyName, City, Address from Customers";         cnn.Open();         SqlDataAdapter ad = new SqlDataAdapter(sqlstr,cnn);         DataTable dt = new DataTable();         ad.Fill(dt);grdCustomer.DataSource = dt;         grdCustomer.DataBind();     }//自动记数函数，在前台调用public int GetCount(){     return ++count ;}