display an extrafield over product image with virtuemart when typed by user (something like tshirt designer)

i need to display an extrafield (virtuemart standard attribute) on flypage over the product image.

I need it as a "customization print option" to display what user want to write over product!

I need the field under other extrafield (as it is normally), but let it appear over image only when user write on it! Is it possible?

Or is there some other solution for this?

Here's the example:

I'm using:

• Joo开发者_开发知识库mla V 1.5.14
• Virtuemart V1.1.6

code are welcome, i'm not so expert! thank you

The first solution that comes to mind is to use Mootools (since VM already loads it) to update a blank div that you position over the top of the image. This is a built in function in Mootools.

http://mootools.net/docs/core/Element/Element#Element%3areplaces