JQuery :: Possible To Trigger External Overlay Via EventListener?

I got the "loading external pages" overlay working just fine from the examples. My project calls for me to open an external overlay but we don't have control over the trigger point. The content is being injected into our pages via an external scripts. So I created an event listener with JQuery to listen for any clicks that occur to a specific link, this works just fine. What I've been struggling to do is open up an external overlay via my listener. I've tried creating a custom function called showOverlay that will do the real work but no luck. Is it possible to trigger an external Overlay via eventListener or do I have to take a different approach?

This is my eventListener.
$('#ExternalLinkReadID a').click(function() {
var id = $(this).attr('href');
alert("before: " + id);
$(this).showOverlay();
alert("after");
});

<a href="readreviews.jsp" rel="#overlay" style="text-decoration:none">
<button type="button">Reviews</button>
</a><!-- overlayed element -->
<div class="apple_overlay" id="overlay"><a class="close"></a>
<!-- the external content is loaded inside this tag -->
<div class="contentWrap"></div>
</div><!-- make all links with the 'rel' attribute open overlays -->
<script>
$.fn.showOverlay = function() {
// if the function argument is given to overlay,
// it is assumed to be the onBeforeLoad event listener
$("a[href]").overlay({
mask: 'lightgrey',
effect: 'apple',
onBeforeLoad: function() {
// grab wrapper element inside content
var wrap = this.getOverlay().find(".contentWrap");
// load the page specified in the trigger
wrap.load(this.getTrigger().attr("href"));
}});};
</script>