Adding interactivity and rollovers…
Once you have created a button, you need to apply an action to it in order to build functionality into your button. You have two controls over the functionality of your button, the Event and Action. The Event allows you to control when the action will become active. The Action controls the behaviour of the button.
Here is a list of the different Events and Actions available:
EVENTS
On Release: When the mouse button is released after a click.
On Click: When the mouse button is clicked (without being released).
On Roll Over: When the mouse pointer enters the button area defined by the button’s bounding box.
On Roll Off: When the mouse pointer exits the button area.
On Focus: When the button receives focus, either through a mouse action or pressing the Tab key.
On Blur: When the focus moves to a different button or form field.
ACTIONS
Close (PDF): Closes the PDF document.
Exit (PDF): Exits the application, such as Adobe Reader, in which the PDF document is open.
Go To Anchor: Jumps to the specified text anchor.
Go To First/Last/Next/Previous Page: Jumps to the first, last, previous, or next page in the PDF or SWF file.
Go To Previous View (PDF): Jumps to the most recently viewed page in the PDF document, or returns to the last used zoom size.
Go To Next View (PDF): Jumps to a page after going to the previous view. In the same way that a Forward button is available in a web browser only after someone clicks the Back button, this option is available only if the user has jumped to a previous view.
Go To Page (SWF Only): Jumps to the page in the SWF file you specify.
Go To URL: Opens the web page of the specified URL.
Movie (PDF): Lets you play, pause, stop, or resume the selected movie.
Open File (PDF): Launches and opens the file that you specify. If you specify a file that is not PDF, the reader needs the native application to open it successfully.
Show/Hide Buttons: Toggles between showing and hiding specified buttons in the exported PDF or SWF file.
Sound (PDF): Lets you play, pause, stop, or resume a sound clip.
View Zoom (PDF): Displays the page according to the zoom option you specify.
InDesign also allows you to add rollover functionality to a button. This can be done from the State Appearances section of the Buttons panel. Once an object has been converted to a button, it now has three different appearances. Normal, Rollover and Click. Normal lets you maintain the original appearance of the button, Rollover is where you can create a different appearance when someone hovers over the button, and Click allows you to have yet another appearance when someone clicks on the button. To change the appearance of a State, simply select your button, then double click on the particular state you are wanting to edit. That appearance will now be active (highlighted in blue), you can edit the object whilst it’s in that appearance, and it will only affect that State. When you’re done editing your appearances, it’s best to double click back on the Normal State so your design looks as expected. When you export to PDF/SWF the rollovers will be present.

For more information on this topic via Adobe help click here.
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