CSS Codes
CSS Layouts

<html>

<head>

<script>

//"Accept terms" form submission- By Dynamic Drive
//For full source code and more DHTML scripts, visit http://www.dynamicdrive.com
//This credit MUST stay intact for use

var checkobj

function agreesubmit(el){
checkobj=el
if (document.all||document.getElementById){
for (i=0;i<checkobj.form.length;i++){ //hunt down submit button
var tempobj=checkobj.form.elements[i]
if(tempobj.type.toLowerCase()=="submit")
tempobj.disabled=!checkobj.checked
}
}
}

function defaultagree(el){
if (!document.all&&!document.getElementById){
if (window.checkobj&&checkobj.checked)
return true
else{
alert("Please read/accept terms to submit form")
return false
}
}
}

</script>

</head>

<body>

<form name="agreeform" onSubmit="return defaultagree(this)">
Rest of your form here<br>
<input name="agreecheck" type="checkbox" onClick="agreesubmit(this)"><b>I agree to the above terms</b><br>
<input type="Submit" value="Submit!" disabled>
</form>

<script>
//change two names below to your form's names
document.forms.agreeform.agreecheck.checked=false
</script>

<p align="center"><font face="Arial" size="-2">Free DHTML scripts provided by<br>
<a href="http://www.dynamicdrive.com">Dynamic Drive</a></font></p>

</body>
</html>