1<script> 2 function toggleDisplay(element, button) 3 { 4 if (element.style.display == "none") 5 element.style.display = ""; 6 else 7 element.style.display = "none"; 8 } 9 10 function toggleVisibility(element, button) 11 { 12 if (element.style.visibility == "hidden") 13 element.style.visibility = ""; 14 else 15 element.style.visibility = "hidden"; 16 } 17 18</script> 19<p> 20 Play with the display and visibility toggles. Make sure that turning an inner element visible does not show it if it has a hidden or 21 non-displaying ancestor, and that making an ancestor visible and displaying shows only its descendants the are visible and displaying. 22</p> 23<table> 24 <tr> 25 <td> 26 <input type="checkbox" checked="true" onclick="toggleDisplay(document.getElementById('middle'))"> Outer frame display 27 </td> 28 <td> 29 <input type="checkbox" checked="true" onclick="toggleDisplay(document.getElementById('middle').contentDocument.getElementById('inner'))"> Inner frame display 30 </td> 31 </tr> 32 <tr> 33 <td> 34 <input type="checkbox" checked="true" onclick="toggleVisibility(document.getElementById('middle'))"> Outer frame visibility 35 </td> 36 <td> 37 <input type="checkbox" checked="true" onclick="toggleVisibility(document.getElementById('middle').contentDocument.getElementById('inner'))"> Inner frame visibility 38 </td> 39 <td> 40 <input type="checkbox" checked="true" onclick="toggleVisibility(document.getElementById('middle').contentDocument.getElementById('inner').contentDocument.getElementById('plugin'))"> Inner plug-in visibility 41 </td> 42 </tr> 43</table> 44 45<iframe id="middle" style="height: 400px; width: 400px;" src="resources/nested-plug-ins-outer-frame.html"></iframe> 46