protected void insert_courses(object sender, EventArgs e) { BLItem objBL = new BLItem(); string courseID = dd.SelectedValue; string teacherID = empID.Text; int temp = objBL.check_Emp_username(teacherID); if (temp == 1) { submit.Visible = false; Button1.Visible = true; DataTable dt = objBL.get_available_sections(courseID); dd1.Visible = true; dd1.DataSource = dt; dd1.DataTextField = "SectionID"; dd1.DataValueField = "SectionID"; dd1.DataBind(); dd1.Items.Insert(0, new ListItem("Select SectionID", "-1")); } else { ScriptManager.RegisterClientScriptBlock(this, this.GetType(), "alertMessage", "alert('Employee Does Not Exist.')", true); } }