protected void btn6_Click(object sender, EventArgs e)
{
// Clear all content output from the buffer stream
Response.ClearContent();
// Specify the default file name using "content-disposition" RESPONSE header
Response.AppendHeader("content-disposition", "attachment; filename=notice.xls");
// Set excel as the HTTP MIME type
Response.ContentType = "application/excel";
// Create an instance of stringWriter for writing information to a string
System.IO.StringWriter stringWriter6 = new System.IO.StringWriter();
// Create an instance of HtmlTextWriter class for writing markup
// characters and text to an ASP.NET server control output stream
HtmlTextWriter htw6 = new HtmlTextWriter(stringWriter6);
GridView7.RenderControl(htw6);
Response.Write(stringWriter6.ToString());
Response.End();
}