protected void ddl_EduLevel_SelectedIndexChanged(object sender, EventArgs e) { string EduLevel = ddl_EduLevel.SelectedItem.ToString(); if (EduLevel == "Any") { GridView1.DataSource = bookstorebo.filterEdulvlAny(EduLevel); GridView1.DataBind(); } else { GridView1.DataSource = bookstorebo.filterEdulvl(EduLevel); GridView1.DataBind(); } }