i get this error: ------ Build started: Project: TestDbReadWrite, Configuration: Debug .NET ------ Preparing resources... Updating references... Performing main compilation... c:\documents and settings\emiel hartman\mijn documenten\visual studio projects\cs\testdbreadwrite\mainconsole.cs(4,20): error CS0234: The type or namespace name 'ADO' does not exist in the class or namespace 'System.Data' (are you missing an assembly reference?) Build complete -- 1 errors, 0 warnings Building satellite assemblies... Satellite assemblies could not be built because the main project output is missing. ---------------------- Done ---------------------- Build: 0 succeeded, 1 failed, 0 skipped