private void btnTeacher_Search_Click(object sender, EventArgs e) { if (Radiobtn_FullName_teacher.Checked == false && Radiobtn_GradeName.Checked == false) { return; } if (Radiobtn_FullName_teacher.Checked == true) { dt_student.DataSource = BUS_Admin.SearchingForTeacherWithName(txtSearch_student.Text, conStrSettings, lbPage_student); } if (Radiobtn_GradeName.Checked == true) { dt_student.DataSource = BUS_Admin.SearchingForTeacherWithGrade(txtSearch_student.Text, conStrSettings, lbPage_teacher); } }