Showing a "Rules" prompt when making a reservation.

The previous example of modifying the New Reservation dialog to add extra prompts can also be extended or other special cases.  (Version 4.0 required.)  

This example shows how to add a prompt for the reservationist to read certain rules to the person reserving the site, before continuing.

1. The first step is to add a Dialog definition that's an Add-on to the New Reservation dialog.  Go to Maintenance / Advanced Customizations / Dialogs, and click "Add dialog definition".

Note: Only one Add-on definition can be active for a given dialog, so if you already had such a definition, e.g. from the previous example, then you would just Edit the existing one and add Elements to it, instead of creating a new one here (skip to step 3).

2. Give it a name, such as "New Reservation add-on".  Then check the "Add-on" box and select "New Reservation" from the list.  We're not adding any new controls to it, so the Width and Height values can remain 0.

3. Now we need to add an action to the dialog that shows a prompt every time they save the reservation.  Click "Add Element", and for the element type select "Action on data saved".

4. We don't really need a Condition for this element (we always want it to show the prompt).  Even though we might not want to show it based on certain things about the reservation, we can't put this in the Condition expression because the Condition is only evaluated when the dialog is first created, not when the action is triggered.

5. Now we need to add an Action expression, which will be executed when the reservation is saved (e.g. "Done", "Continue", or any other button clicked that would normally save the reservation).  Enter the following Action expression to show a prompt with a simple OK button:

MessageBox("TELL THE CUSTOMER: \n\n Deposit is due in 10 days.")

Note that you can add as much text as you want in the message, but you can't enter line breaks when you type the expression text.  Instead, insert the characters "\n" wherever you want to start a new line (two in a row, as shown above, makes a blank line).

6. Now just Save the element, and we're done with the customization.