On a dialogue box (or any other control) you can set conditional formatting that can "Hide" a control based on a condition.... so for instance a condition can be:
If button A is pressed set attribute1 to 1
Conditional formatting of diplay box
If attribute1 = 0 then hide
Using this approach means you have an unattached attribute called attribute1. Set the button to change the attribute to 1 when pressed and make sure it defaults to 0.
Set the conditional formatting of your display box to "If attribute1 = 0 then hide" and et viola! When the button is pressed the dialog box will appear.
This approach can be used with all types of control.
You can also use repeating sections in some circumstances, and you can combine repeating sections with conditional formatting.
hope that helps