Database Connection handle Error

Question

Hi all, I download DataServices from http://www.c-sharpcorner.com/Database/CDataServiceClassMYY.asp. It works well if I run a query and close connection such as MustClose = true; SelectSqlData(QueryString, TableName, MustClose); But if I don't close connection after running some Queries such as MustClose = false; SelectSqlData(QueryString, TableName, MustClose); I've got the error: An unhandled exception of type 'System.InvalidOperationException' occurred in mscorlib.dll Additional information: Handle is not initialized Could you please help me to tell me what is wrong. Thanks so much Khai Hoang