Export Gridview to Excel in ASP.NET

i'm using the below code toexport the gridview to Excel,i got code from net..so any one pls let me knw the process of the code.....

Response.Clear();
        Response.Buffer = true;
        Response.AddHeader("content-disposition","attachment;filename=g.xls");
        Response.Charset = "";
        Response.ContentType = "application/vnd.ms-excel";
        StringWriter sw = new StringWriter();
        HtmlTextWriter ht = new HtmlTextWriter(sw);
        GridView1.AllowPaging = false;
        GridView1.DataBind();
        GridView1.RenderControl(ht);
        Response.Output.Write(sw.ToString());
        Response.Flush();
        Response.End();

Tags: ASP.NET