Mire esto ....
Código HTML:
Ver original
<p>Click the button to wait 3 seconds, then alert "Hello".
</p> <p>After clicking away the alert box, an new alert box will appear in 3 seconds. This goes on forever...
</p>
<script type="text/javascript"> function myFunction()
{
setInterval(function(){alert("Hello")},3000);
}
y para documentacion ....
http://www.w3schools.com/js/js_timing.asp
Intentelo y si logra algo le ayudo a terminarlo.