The gRbase package is intended to set the framework for computer packages for data analysis using graphical models. The gRbase package is developed for the open source language, R, and is available for several platforms. The package is intended to be widely extendible and flexible so that package developers may implement further types of graphical models using the available methods. The gRbase is used together with gRain which has same specifications as for gRbase. In this paper, we show how these building blocks can be combined and integrated with inference engines in the special cases of conditional probabilities of random variables asoociated with real life problems. We also illustratehow to use the package to deal with a simple case scenario of the problem of HIV and OSTDs in Nairobi.