I'm making up some forms for my site and was wondering if anyone knows some JS for this:-

When the form is submitted the user gets sent to a page which says "Thankyou for your submission..blah, blah, blah.....".
I would like this page to automatically change back to the page they came from prior to filling out the form after 3 seconds, rather than having to click out of it.

I believe this could be done using "javascript:history.go(-2);" (which takes them back the two pages I require), but I haven't got a clue on how to set this to occur after a period of 3 seconds.

Any help appreciated.