with a dynamic framework, you need to have a variable and value pair. usually a query string variable is used, but it could also be a session variable.
the name of the variable and value are defined by you. In the feature tour, they are using the URL variable named "form", but you can use anything you like.
form was chosen because they are using a form page, the form querystring value is determining which form will be used. if the contact page is access with out a querystring variable:
it will load the contact_form.php page as a plugin
if there is a form querystring variable and it is equal to question, this will trigger the question_form.php plugin page to be loaded instead:
you can use any variable name / value you like. in data assist, it may make sense to use "action" as the name
and set it up so that the default is the search page:
index.php - would load the search page
set the value results to load the data assist results page:
insert to load the DataAssist insert page:
Update for the update page
delete for the delete page
and detail for the detail page.