Firing a .net event via an iframes parent

 Hi,
I have an iframe that is loaded up in a lytebox (http://www.dolem.com/lytebox). In the iframe, I have a pretty standard .net page with an imagebutton. I want to be able to fire the postback event for the image via the parent document.
 
So far, I can access the contents of the the iframe with some javascript that looks like this:
                             window.frames['lbIframe'].document.form1.submit();
Of course, this does not wire the click event properly. SO I tried something like this:
                            window.frames['lbIframe'].document.form1.WebForm_DoPostBackWithOptions(new WebForm_PostBackOptions("eventDocumentLog$ctl00$btnSave", "", true, "", "" ...