JavaScript function to make button active

[Ntrimgs]

I need to force the user of a web page to accept the terms of use agreement before being allowed to proceed. To accept the terms, the user just needs to click a checkbox. I then want the "Next" button located below it to then become active. Can this be done with a JavaScript function?

[rh_lloydnorthov]

Example HTML

<form name="terms" id="terms" method="post" action="process.php">
	<input type="checkbox" id="accept_terms" value="accept"/><label for="accept_terms">I accept the terms and conditions</label>
	<input type="submit" id="terms_submit" value="Submit" />
</form>

// jQuery
$(document).ready(function(){
	// disable submit button on page load using javascript
	$('#terms_submit').attr({ "disabled" : true });

	// toggle submit button disabled state based on state of check box, triggered when uses clicks on check box / label
	$('#accept_terms').click(function(){
		$('#terms_submit').attr({ "disabled" : !$('#accept_terms').attr('checked') });
	});
})

// vanilla javascript
window.onload = function(){
	// disable submit button on page load using javascript
	document.getElementById('terms_submit').disabled = true;
	
	// toggle submit button disabled state based on state of check box, triggered when uses clicks on check box / label
	document.getElementById('accept_terms').onclick = function(){
		document.getElementById('terms_submit').disabled = !document.getElementById('accept_terms').checked;
	}
}