how to edit perticular cell in a gridview using single click

<div style="text-align: center; background-color: SkyBlue; width: 100%">

<h3>

GridViewh3>

<asp:GridView ID="gridview1" runat="server" AutoGenerateColumns="false" AlternatingRowStyle-BackColor="Gray"

Font-Bold="true" Width="100%" > <%--OnRowDataBound="gridview1_OnRowDataBound" --%>

<Columns>

<asp:BoundField DataField="Id" HeaderText="Id" ItemStyle-Width="50" />

<asp:BoundField DataField="Name" HeaderText="Name" ItemStyle-Width="50" />

<asp:BoundField DataField="City" HeaderText="City" ItemStyle-Width="50" />

<asp:TemplateField>

<ItemTemplate>

<asp:Label ID="lbl1" runat="server" Visible="false">asp:Label>

ItemTemplate>

asp:TemplateField>

Columns>

asp:GridView>

protected void Page_Load(object sender, EventArgs e)

if (!this.IsPostBack)

DataTable dt = new DataTable();

dt.Columns.AddRange(new DataColumn[3] { new DataColumn("Id"), new DataColumn("Name"), new DataColumn("City") });

dt.Rows.Add(1, "Anamika", "Bangalore");

dt.Rows.Add(2, "Sunny", "Chennai");

dt.Rows.Add(3, "Monika", "Bangalore");

dt.Rows.Add(4, "Jyoti", "Chennai");

dt.Rows.Add(5, "Radhika", "Jabalpur");

dt.Rows.Add(6, "Imran", "Jammu");

dt.Rows.Add(7, "Alok", "Delhi");