... The distinction of our approach is in that we unite the Actor Prolog concurrent ob ject-oriented logic language [ 1,2,3] with the Structural Analysis and Design Technique (SADT) diagrams to obtain new issues in the following areas: 1. ... Graphic user interface management. ... The individual blocks of visual user interface based on the SADT diagrams are implemented by using parallel processes of Actor Prolog. ... We applied the visual programming method for logic programming of Internet agents [4]. ...