If you are just looking to update a number at regular intervals, then using the setInterval function is probably what you'll want to use, possibly with some textfield in a form or other means of presenting the number value. Here's a link that discusses both the setTimeout and setInterval functions.
setInterval is probably more appropriate because the setTimeout function only triggers once while setInterval triggers continuously until you tell it to stop.
Thanks for the replies. Cowboy, that link doesnt work. Thanks though.
setInterval ( "doSomething ()", 5000);
function doSomething ( )
// (do something here)