/*
 * only real people can submit this form
 */
/*
 * Use like this:

<style type="text/css">
.invisible {
	display: none;
}
</style>
...
<form method="post" id="theForm" action="onlyhumanscandothis">
...
<span id="javascriptRequired">Javascript is required to use this form. Please enable Javascript in your web browser.</span>
<input type="submit" id="submitButton" class="invisible">
<script type="text/javascript" src="RealPeople2.js"></script>
<script type="text/javascript">
	document.getElementById('theForm').action = "/cgi-bin/realActionValue";
	rp2addClass("javascriptRequired", "invisible");
	rp2removeClass("submitButton", "invisible");
</script>

 */

var rp2ClassNameCache = {};

function rp2getClassRegEx(className)
{
    var re = rp2ClassNameCache[className];
    if (!re) {
        re = new RegExp('(?:^|\\s+)' + className + '(?:\\s+|$)');
        rp2ClassNameCache[className] = re;
    }
    return re;
};

function rp2hasClass(obj, className)
{
    var re = rp2getClassRegEx(className);
    return re.test(obj.className);
}

function rp2addClass(id, className)
{
	var obj = document.getElementById(id);
	if (rp2hasClass(obj, className))
	{
		return false;
	}
	obj.className = [obj.className, className].join(' ');
	return true;
}

function rp2removeClass(id, className)
{
	var obj = document.getElementById(id);
	if ( ! rp2hasClass(obj, className))
	{
		return false;
	}
	var c = obj.className;
	var re = rp2getClassRegEx(className);
	obj.className = c.replace(re, ' ');
	return true;
}