<p>Click on an Overlay, to switch it's zIndex with the highest zIndex in the stack, bringing it to the top of the stack:</p>

<div class="overlay-example" id="overlay-stack">

<p class="filler">

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<select class="needs-shim">

<option>Prevent IE6 Bleedthrough</option>

</select>

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</p>

</div>

<script type="text/javascript">

YUI().use("overlay", function(Y) {

var overlays = [],

overlay,

n = 6,

xy = Y.one("#overlay-stack").getXY();

function getOverlayXY(xy, i) {

return [xy[0] + i * 60, xy[1] + i * 40];

}

for (var i = 0; i < n; ++i) {

ovrXY = getOverlayXY(xy, i);

ovrZIndex = i+1;

// Setup n Overlays, with increasing zIndex values

overlay = new Y.Overlay({

zIndex:ovrZIndex,

xy:ovrXY,

width:"8em",

height:"8em",

headerContent: 'Overlay <span class="yui3-ovr-number">' + i + '</span>',

bodyContent: "zIndex = " + ovrZIndex

});

overlay.render("#overlay-stack");

overlays.push(overlay);

// Update body whenever zIndex changes

overlay.after("zIndexChange", function(e) {

this.set("bodyContent", "zIndex = " + e.newVal);

});

}

function onStackMouseDown(e) {

var widget = Y.Widget.getByNode(e.target);

// If user clicked on an Overlay, bring it to the top of the stack

if (widget && widget instanceof Y.Overlay) {

bringToTop(widget);

}

}

// zIndex comparator

function byZIndexDesc(a, b) {

if (!a || !b || !a.hasImpl(Y.WidgetStack) || !b.hasImpl(Y.WidgetStack)) {

return 0;

} else {

var aZ = a.get("zIndex");

var bZ = b.get("zIndex");

if (aZ > bZ) {

return -1;

} else if (aZ < bZ) {

return 1;

} else {

return 0;

}

}

}

function bringToTop(overlay) {

// Sort overlays by their numerical zIndex values

overlays.sort(byZIndexDesc);

// Get the highest one

var highest = overlays[0];

// If the overlay is not the highest one, switch zIndices

if (highest !== overlay) {

var highestZ = highest.get("zIndex");

var overlayZ = overlay.get("zIndex");

overlay.set("zIndex", highestZ);

highest.set("zIndex", overlayZ);

}

}

Y.on("mousedown", onStackMouseDown, "#overlay-stack");

});

</script>