Creating complex multimedia presentations involves the specification of temporal and spatial relations in the form of constraints. However, some of these constraints could contradict each other and hence lead to an inconsistency. The user may not be aware of this inconsistency while authoring. Hence this inconsistency has to be identified and removed by the presentation process prior to the play-out. In this paper, we examined an existing work based on graph theory for consistency checking. We propose a modification to this approach which simplifies the algorithm, reduces its total running time, and helps to make it dynamic. Another salient feature of our paper is the introduction of new temporal and spatial operators with higher expressive power than traditional ones. Thus, this paper presents a multimedia presentation mechanism, which dynamically maintains a consistent and complete set of constraints during authoring and play-out of the presentation.