[TP]

Thanks, that works really well. Whilst you were doing that, I had a go at using some other code I'd used in the past to show/hide layers and got it to work with the checkbox. I used your code in the end, but this also works:

Here is the code:

hide_block_script.tpl

{literal} 
<script>
function toggle(theImg, divName){
  if(theImg.value!='on'){
    theImg.value='on'
  } else {
    theImg.value='off'
  }
  divStyle = document.getElementById(divName).style;
  if(theImg.value=='on'){
    divStyle.display='block';
  } else {
    divStyle.display='none';
  }
}
</script>
{/literal}

Skin1\customer\main\checkout.tpl:

{include file="hide_block_script.tpl"}

 
<input type="checkbox" name="checkbox" value="checkbox" onclick="toggle(this,'wrapper');"> I Agree to the Terms and Conditions

<div id="wrapper" style="display:none">{include file="buttons/button.tpl" button_title=$lng.lbl_submit_order style="button" href=$button_href} 
{else} 
{include file="submit_wo_js.tpl" value=$lng.lbl_submit_order} 
{/if} </div>