// VB.NET
Try
connectUser = ConfigurationManager.AppSettings("DB_User_ID").ToString
Catch error_occure As Exception
connectUser = ""
End Try
// c# from conversion
try {
connectUser = ConfigurationManager.AppSettings("DB_User_ID").ToString;
} catch (Exception error_occure) {
connectUser = "";
}
// inform about AppSettings[" "] and no ToString
connectUser = ConfigurationManager.AppSettings["DB_User_ID"];
Thank you