Confusingly, or perhaps not, I don't want it to postback, as it is loading a popup containing content, but the postback closes the popup. 

The code is really simple, and its just a bog standard `asp:Hyperlink`. Theres nothing that I can see which could cause this, and I am mainly confused as to how and why it is being handled so differently by each browser. 

The only thing I could think of was JS with 

```
event.preventDefault();

```

Any one got any ideas what could cause this?

I am reloading an iFrame with a new source, which sits on the page, but it is forcing the entire page to postback on firefox only. 

```
iFrame.attr('src', newSrc);

```

The rest of the code:

```
$('.button-try-glasses').on('click', function (event) {
    var modal = $('#modal-container');
    var newAsset = $(this).attr('data-asset');
    var iFrame = modal.find('iframe');
    var currentIFrameSrc = iFrame.attr('src');

    var newSrc = currentIFrameSrc.substring(0, (currentIFrameSrc.lastIndexOf("/") + 1)) + newAsset;

    iFrame.attr('src', newSrc);
    Trylive.parse();
    showPopup($(null), '#modal-container', true);
    event.preventDefault();
});

```

If I comment out the `.attr` line, it doesn't update the source, but it also doesn't postback and then close the component.