[jQuery] creating modal layer on the fly?

[alivemedia]

I am trying to write my own little modal popup script and it's working
fine in FF but not in IE7.  In IE7 the modal layer shows up on top of
the content I want displayed even though I believe I have the Z-
Indexes set properly.

Anyone run into this an know how to overcome it?

I know there are other pre-written solutions out there but I wanted to
create my own.

Here is my code so far, I know it is rough - plan on cleaning it up
once I get the functionality working:

$(document).ready(function(){

 setupPopup('linkSuggest');

 function setupPopup(id) {
   var lnk= $('.'+id);
   var div = $("div[title='" + id + "']");

   div.attr("class","alivePopupHidden");
   div.prepend("<div class='alivePopupHeader'><a href='#'
class='aliveCancelButton'>[x] cancel / close window</a></div><br
clear='all'/>"); // Add Cancel Link
   var cancelLnk=$("div[title='" + id + "'] .aliveCancelButton"); //
Find cancel link
   cancelLnk.click(function(){hideAllPopups();return false;}); //Add
close behavior
   lnk.bind("click", function(e){   hideAllPopups();
 
div.attr("class","alivePopupVisible");
                                        $('#<
%=txtCurrentSuppliment.ClientID %>').attr('value',this.title);
                                        $('#<
%=hiddenCurrentSupplimentID.ClientID %>').attr('value',this.id);
                                        $('body').append("<div
id='overlay'></div>");
                                        div.css("z-index","999");
                                        return false;}) //Add open
behavior
 }
 function hideAllPopups() {$('div#overlay').remove();$
('.alivePopupVisible').attr("class","alivePopupHidden"); } //Hide all
other popup windows
});


html
---------------
<div title="linkSuggest">
<p>content goes here</p>
</div>