1. A computer system comprising: an object-action manager for building and operating a developer-defined user interface within predetermined parameters, the developer-defined user interface managing interaction between an end-user and an application created by a developer, the object-action manager further comprising parser means for reading a description file and creating data structures from the description file, the description file being created by the developer using a simple definition syntax, the parser means creates the data structures according to a late binding convention; object-list builder means connected to the parser means for defining an object-list interface screen according to the predetermined parameters and the data structures created from the description file; dialog-box builder means connected to the parser means for defining a task dialog interface screen and a step menu interface screen, both according to the predetermined parameters and the data structures created from the description file; library means connected to the object-list builder means and the dialog-box builder means for storing and operating access functions used during operation of the developer-defined user interface; and display handler means connected to the object-list builder means, the dialog-box builder means and the library means, the display handler means for displaying at least one interface screen and managing interaction between the end-user and the application created by the developer.