Don't know how to program something

Hi all,

First of all, thanks for trying to help me.
I want to program something but I don't know how.
I want to program a pop-up which will appear if the user clicks on a specific button on the website.
The pop-up has to be this image.

http://www.habbies.nl/images/v37_alert.gif

But I have a version with the text deleted, so I can add text in the code itself because I don't need that message. Also, I have to get another button image for when they hover over the "ok" button right?


Can someone tell me how to program this??

Thanks,
Shortey

- - - Updated - - -

anyone?