Hmm, little bit vague, but hope this helps...
animation in javascript is usually done using setTimeout (you could use setInterval, but setTimeout is supported by more browser versions). The idea is, you design your algorithm as itterations that move your animation forwards one step and then schedule the next move in a short period of time (about 40ms results in about 25 itterations per second)
So, so long as you always call window.setTimeout("MyAnimate();",40); at the end of your animation function, it will continue forever (Watch out for exceptions though).
For example, in the circle animation:
function Animate()
{
var nKids = data.kids.length;
for ( var i = 0; i < nKids; i++ )
{
var kid = data.kids[i];
kid.angle += data.dAngle;
kid.oDiv.style.top = Math.round(-Math.cos(kid.angle) * data.radius + (data.mum.height - kid.height) / 2);
kid.oDiv.style.left = Math.round(Math.sin(kid.angle) * data.radius + (data.mum.width - kid.width) / 2);
}
window.setTimeout("Animate();",data.dTime);
}
The Animate() function performs one itteration of the circle by cycling through each 'kid', adding a preset angle to the current one and then calculating the position coordinates for the <div> tag for that kid.
does this help?