Magento: How to redirect on form submit - forms

Question

I'm using Magento CE 1.7.
I created a CMS page to add 'Terms Of Use' to it and at the bottom of the page I added a simple "Accept Terms" submit form to have the customers agree to the terms before they can access the page I want them to access. Here's the code.
<form action="url-to-go-to.html" method="GET" onsubmit="return checkCheckBox(this)">
I accept: <input type="checkbox" value="0" name="agree">
<input type="submit" value="Continue">
<input type="button" value="Exit" onclick="document.location.href='BACKTOWHAT.html';">
</form>
<script type="text/javascript">
<!--
function checkCheckBox(f){
if (f.agree.checked == false )
{
alert("Please tick the box to continue");
return false;
} else
return true;
}
-->
</script>
The only problem I have is that in I can only get it to work by entering the URL to the page I want them to be redirected to. i.e.
<form action="domainname.com/shop.html"> <!-- store section to go to -->
/* and the same goes for */
onclick="document.location.href='domainname.com';"> <!-- back to storefront -->
I wanted to use something else rather than the URL but I'm not sure how to do it. I thought using something like this would work.
<form action="<?php echo $this->_redirect('shop.html'); ?>" method=.... >
but it didn't.
I believe if this has been within a .phtml file it would've worked but I'm working with a simple CMS page and I know magento functions work in CMS pages but I don't know a function that would work for this purpose.

Answer 1

Ok, I figured it out after testing a bit more. (I'm still learning how to code)
It's quite simple, the form action should be like this instead.
<form action="{{store direct_url='shop.html'}}" method=..... >
and to redirect back to the store front on "exit" this is what worked.
onclick="document.location.href='{{store direct_url=' '}}
This worked perfectly. hope it helps others.