Gravity form with FancyBox

Hi,

I'm using a plugin called Easy FancyBox.
I have this page https://clevelandkollel.com/534-2/ set that when someone clicks on the image it brings up the form.
When a user successfully inputs all required field, he gets redirected to a thank you page.
If there's an error however, the form just close and the user stays on the same page.
The user has no way of knowing that his form wasn't processed.
if the user opens the form again all the missing information fields will be highlighted in red.

Is there a way to prevent the popup from closing on error?
Is there a way to only display the submit button if there are no errors?
Any other ideas how i can get around this problem?

Here's the content of my post :

<div class="fancybox-hidden" style="display: none;">
<div id="fancyboxID-1" style="width: 550px; height: 1250px;">[gravityform id="5" name="Raffle"]

</div>
</div>
<a class="fancybox" href="#fancyboxID-1"><img  src="http://clevelandkollel.com/wp-content/uploads/2012/12/Raffle_January.jpg"  /></a>

Thanks in advance.

Thanks David, that will probably be complicated.
Is there a way to prevent the "submit" button from appearing unless all required info was inputted?

Thanks!