How to set link one of my datafield column in gridview

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False">
       <Columns>
           <asp:TemplateField>
               <ItemTemplate>                 
                        <a href= "<%# Eval("address") %>"  id="a1" > Click here</a>

               </ItemTemplate>
           </asp:TemplateField>
       </Columns>
   </asp:GridView>

if (!IsPostBack)
        {
            using (SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["testConnectionString"].ConnectionString))
            {
                con.Open();
                using (SqlCommand cmd = new SqlCommand("select * from test1", con))
                {
                    DataTable dt = new DataTable();
                    SqlDataAdapter adpt = new SqlDataAdapter(cmd);
                    adpt.Fill(dt);
                   GridView1.DataSource = dt;
                  GridView1.DataBind();
                }
            } 
        }