Use of HTML forms in complex user interfaces for server-side applications

It is now commonplace to use forms within HTML documents to have server-based applications interact with remote users. However, these forms are, most of the time, rather simple and only allow a one time interaction between the user and the application. Forms are nevertheless very versatile and can be used to build rather complex user interfaces for server-side applications that involve multiple interaction loops. In this paper, we describe how our students used such forms to remotely control a symbolic debugger executing algorithms in the on-line version of a book used in their data structure course. After describing in detail how the user interface is built and how the students can interact with it, we focus on the limitations of this approach and how this interface could be enhanced with the use of more recent developments such as applets.