protected void ButtonDel_Click(object sender, EventArgs e)
{
if (Request.QueryString["Cid"] != null)
{
string Cid = Request.QueryString["Cid"];
LearnSite.BLL.Courses coursebll = new LearnSite.BLL.Courses();
coursebll.Delete(Int32.Parse(Cid));
System.Threading.Thread.Sleep(1000);
Response.Redirect("~/Teacher/course.aspx", false);
}
}