To do this is not very easy...what you see there and on the front page of the Tanx page is called Flash animation and you need to have a Flash editor to create the animations. I recommend getting one from
http://www.swishzone.com
they have several versions on trial and one lite version for unlimited use. You will need to learn the software beforehandespcially for the trial versions like swishmax or swish2 because there are many advanced features, and you'll only have so many days to get your animation on the web.
Once you get a nice Flash intro you will be ready to embed it into a HTML document. Once you do this just post and I will give the necessary code for this.