Each course has numerous pages with information. These pages may include class policies, class notes, exam problems, grade centers, course recordings, information about office hours, information about special events, etc. A course is rarely a single web page. Most of the time, a course is an entire web-page system.

When instructors teach the same course several times, they often can re-use the majority of the web-page system. However, almost every page in the system will have some information that needs to change. The dates for the exams are definitely going to change from one semester to another. The year will most likely change after every January 1st. In addition, some of the components are the same for several courses. The dates of the holidays are the same for all courses in a given semester. In the dreams of extremely organized professors, the due dates for the homeworks should also be the same for all courses.

The maintenance of web-page systems is greatly simplified with the introduction of variables. You can create a special document that contains all the variables. In the next section we will show how this is done using one example


We first create a text document called fall2021Math001Variables. The type of the document should be systemText. This change is achieved by modifying systemData section of the page (this section is modified by clicking on the button advanced instead of the button edit). In this document you can define the variables that can later be used across multiple pages.

If we want to define three variables called courseName, semester, and midterm1Date, we need to put the following text in the main text data section of the page:

_vl_Introduction to Arithmetic_/vl_

_vl_Fall 2021_/vl_
_vl_Monday, October 4, 2021_/vl_

We will now describe how these variables are used in multiple text documents. Assume that our course web-page system consists of the following pages: math001Fall2021Main, math001Fall2021Policies, and math001Fall2021Assignments. In the beginning of each of those pages we need to announce that we are using the document fall2021Math001Variables that contains the variables. Then we can use the variables inside the text.