OnPreview and OnGenerate event in FormAPI

syim

On a TeamSite form, after you click the Generate button, a preview page will pop up. Does that mean an "OnPreview" event will get triggered after Generate?

I did a simple test on my included js like followings, but the alert popup box did not show up. Any idea how we can get an alert popup to show up after generate and before previewing a page?

function init() {
IWEventRegistry.addFormHandler("OnPreview", handle_preview);
}

function handle_preview()
{
alert("on preview");
}

IWEventRegistry.addFormHandler("onFormInit", init);