This.each and a callback function

Question

Hi all
I am having trouble working out how to get this to work. I have a $this.each function that gets all the relavent .attr('href') and I do a replace on it. All this works fine.
When I do the replace is the item I want is not valid then I need it to stay the same else I get an error. Now to to this I am using function IsValidImageUrl(url). This works but because you cannot turn an asynchonous call into a synchronous one I need to make a callback.
But here is my problem all the bits work but I cannot get the code to work together because I am using a this.each and the call back. with the validation and I am really stuck. The code is below it is in it bit as I have tried eveything and am just not getting it. Can someone help or point me in the right direction.
Cheers Daniel
$this.each(function  {
     var myItem = jQuery(this)
     var myLarge = myItem.attr("href");
     myZoom = myLarge.replace('lrg', 'zoom')
     myItem.attr("href",myZoom);
     myItem.attr("rev",myLarge);
function myCallback(url, answer) {
          if (answer==false) {
          myItem.attr("href",myLarge);
          myItem.attr("rev",myLarge);
                              } else {
          myItem.attr("href",myZoom);
          myItem.attr("rev",myLarge);   
function IsValidImageUrl(url, callback) {
    var img = new Image();
          alert(myZoom);
          img.onerror = function() { callback(url, false); }
    img.onload =  function() { callback(url, true); }
    img.src = url
IsValidImageUrl(myZoom, myCallback);

Answer 1

So you basically have large product layout and when you hover over the image there it does a zoom effect?
If so then you can have a big image for your zoom and for your large image by default use _path in the image tag with thumbnail paramater in the URL to make a smaller version of it outlined in the BC documentation online.
Many jQuery image zoom plugins will then work. Slight tweaks to that will work.
If your doing it on the list view then same thing applies with the _path as a link source to fetch.