private void LoadClasses(Guid departmentValue) { ClassList cList = new ClassList(); //ddlDepartment.Visible = true; if (ddlDepartment.SelectedValue != null) { cList = cList.GetClassesByDepartmentId(departmentValue);//Get Department Id By Department Name selected ddlSelectClass.DataSource = cList.List; ddlSelectClass.DataBind(); ddlSelectClass.Items.Add("Choose Class"); ddlSelectClass.SelectedValue = "Choose Class"; ddlSelectClass.Visible = true; } btnAddStudents.Visible = true; }