Zimlet Tab with a close button

Hi,

I am new to Zimlets. I am trying to create a zimlet which works as:
- In an email body, when the user hovers on a URL, a pop-up window is created which gives a preview of the URL.
- When the user clicks on the URL, the page is loaded within an iframe, in a new tab.

I need to have a close functionality on the new tab (as in 'New message'/'Compose' tab).

I am able to do it as a 2-stage operation : 1) Delete the button 2) Pop out the current view.

I think there can be an elegant solution to do this. Can anybody help me with this?

Thanks,
Toby