protected void InitializeModalDropDownSupervisor() { int userid = Convert.ToInt32(modalDropDownUsers.SelectedItem.Value); int deptid = Convert.ToInt32(modalDropDownDepartment.SelectedItem.Value); User user = new User(); var data = user.GetAvailableSupervisors(userid, deptid); modalDropDownSupervisor.DataSource = data; for (int i = 0; i < gridViewModal.Rows.Count; i++) { Label labelSupId = (Label)gridViewModal.Rows[i].FindControl("modalLabelSupId"); int lid = Convert.ToInt32(labelSupId.Text); for (int j = 0; j < data.Count; j++) { if (data[j].Id == lid) { data.RemoveAt(j); break; } } } modalDropDownSupervisor.DataTextField = "fullname"; modalDropDownSupervisor.DataValueField = "Id"; modalDropDownSupervisor.DataBind(); if (modalDropDownSupervisor.Items.Count < 1) modalBtnAdd.Visible = false; else modalBtnAdd.Visible = true; }