|Used By:||input, All block elements|
Theand attributes can be used on any block element, although typically they're used on input elements. They can specify an action to perform when the mouse moves into or out of the block, in the same way as with HTML - although unlike HTML but like the href tag, these can be applied to any block element, not just the a element.
This causes the specified button to appear only when the mouse is over the image
<input type="button" visibility="hidden" name="popup" value="This button is hidden!"/> <img src="myimage.jpg" onMouseOver="pdf:show(popup)" onMouseOut="pdf:hide(popup)"/>