The following code shows the implementation of this validate() function.
The script has a catalog of almost all the common validation types built-in.
The idea is to create a set of “validation descriptors” associated with each element in a form.
Note Front Page Server Extensions are a set of programs that provide access to special Front Page features, such as database processing, form processing, hit counters, and other built-in Front Page components that require server-side processing.
You can provide custom validation for your forms in two ways: server-side validation and client-side validation.