Modal dialog open when 'Email a Friend' clicked

I want to open a Modal box when "Email a friend" button is clicked on products detail. It is now moving the content to next location, but instead it should open a modal box with same content with same functionality.

please help required. any idea share it.

You might try this plugin. I'm not sure if it's exactly what you are wanting, but I know that it has a special Email a Friend page, and several ways to draw visitors attention to it.

If above plugin will not help you, you need to call magnific pop-up. The best practice would be to develop plugin which override existing rules.