repeater edit using ajax

<div>
        <asp:ScriptManager ID="ScriptManager1" runat="server">
        </asp:ScriptManager>
        <asp:UpdatePanel ID="UpdatePanel1" runat="server">
        <ContentTemplate>
        <asp:Repeater ID="Repeater1" runat="server" OnItemCommand="Repeater1_ItemCommand"
            OnItemDataBound="">
            <ItemTemplate>
                <asp:Label ID="Label2" runat="server" Text='<%# Eval("ContactName") %>'></asp:Label>&nbsp;
                <asp:Label ID="Label1" runat="server" Text='<%# Eval("ContactID") %>'></asp:Label>

                <asp:Button ID="Button1" runat="server" Text="view" CommandArgument='<%# Eval("ContactID") %>' CommandName="view" />
                <asp:Button ID="Button2" runat="server" Text="view" CommandArgument='<%# Eval("ContactID") %>' CommandName="edit" />
            </ItemTemplate>
        </asp:Repeater>
            <br /><br />

            <div id="div1" runat="server" Visible="false" style="background-color: #FF66FF">
            <div>
            name =
                <asp:Label ID="Label1" runat="server" Text="" Visible="false"></asp:Label>
                <br />
                <asp:TextBox ID="TextBox1" runat="server" Visible="false"></asp:TextBox>
                <input id="btn1" type="button" value="submit" onclick="return btn1_onclick()" />
            </div>
            </div>
        </ContentTemplate>
        </asp:UpdatePanel>
    </div>

protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                DataTable table = new DataTable();
                table.Columns.Add("ContactID", typeof(int));
                table.Columns.Add("ContactName", typeof(string));


                //
                // Here we add five DataRows.
                //
                table.Rows.Add(25, "Indocin");
                table.Rows.Add(50, "Enebrel");
                table.Rows.Add(10, "Hydralazine");
                table.Rows.Add(21, "Combivent");
                table.Rows.Add(100, "Dilantin");

                Repeater1.DataSource = table;
                Repeater1.DataBind();
            }
            
        }

        

        protected void Repeater1_ItemCommand(object source, RepeaterCommandEventArgs e)
        {
            if (e.CommandName == "view")
            {
                string la = ((Label)Repeater1.Items[e.Item.ItemIndex].FindControl("Label2")).Text;
                //Response.Write("<script>alert('" + la + "');</script>");
                Label1.Text = la;
                //Label1.Attributes.Add("display","block");
                div1.Visible = true;
                Label1.Visible = true;
            }
            else if(e.CommandName=="edit")
            {
                TextBox1.Text = ((Label)Repeater1.Items[e.Item.ItemIndex].FindControl("Label2")).Text;
                //Label1.Attributes.Add("display","block");
                div1.Visible = true;
                TextBox1.Visible = true;
            }
        }