var Punbb = {
	/* attach FN to WINDOW.ONLOAD handler */
	addLoadEvent: function(fn)
	{
		var x = window.onload;
		window.onload = (x && typeof x=='function') ? function(){x();fn()} : fn;
	},
	/* return TRUE if node N has class X, else FALSE */
	hasClass: function(n, x)
	{
		return (new RegExp('\\b' + x + '\\b')).test(n.className)
	},
	/* add X class to N node, return TRUE if added, FALSE if already exists */
	addClass: function(n, x)
	{
		if (Punbb.hasClass(n, x)) return false;
		else n.className += ' ' + x;
		return true;
	},
	/* remove X class from N node, return TRUE if removed, FALSE if not present */
	removeClass: function(n, x)
	{
		if (!Punbb.hasClass(n, x)) return false;
		x = new RegExp('\\s*\\b' + x + '\\b', 'g');
		n.className = n.className.replace(x, '');
		return true;
	},
	/* blink node N twice */
	blink: function(n, i)
	{
		if (typeof i == 'undefined') i = 2;
		var x = n.style.visibility;
		if (i && x!='hidden')
		{
			n.style.visibility = 'hidden';
			setTimeout(function(){n.style.visibility=x}, 200);
			setTimeout(function(){Punbb.blink(n,i-1)}, 400);
		}
	},
	/* return true if node N scrolled into view, else false (y axis only) */
	onScreen: function(n)
	{
		function pageYOffset() // return number of pixels page has scrolled
		{
			var y = -1;
			if (self.pageYOffset) y = self.pageYOffset; // all except IE
			else if (document.documentElement && document.documentElement.scrollTop)
				y = document.documentElement.scrollTop; // IE 6 Strict
			else if (document.body) y = document.body.scrollTop; // all other IE ver
			return y;
		}
		function innerHeight() // return inner height of browser window
		{
			var y = -1;
			if (self.innerHeight) y = self.innerHeight; // all except IE
			else if (document.documentElement && document.documentElement.clientHeight)
				y = document.documentElement.clientHeight; // IE 6 Strict Mode
			else if (document.body) y = document.body.clientHeight; // all other IE ver
			return y;
		}
		function nodeYOffset(n) // return y coordinate of node N
		{
			var y = n.offsetTop;
			n = n.offsetParent;
			return n ? y += nodeYOffset(n) : y;
		}
		var screenTop = pageYOffset();
		var screenBottom = screenTop + innerHeight();
		var nodeTop = nodeYOffset(n);
		var nodeBottom = nodeTop + n.clientHeight;
		return nodeTop >= screenTop && nodeBottom < screenBottom;
	},
	/* apply FN to every ARR item, return array of results */
	map: function(fn, arr)
	{
		for (var i=0,len=arr.length; i<len; i++)
		{
			arr[i] = fn(arr[i])
		}
		return arr;
	},
	/* return first index where FN(ARR[i]) is true or -1 if none */
	find: function(fn, arr)
	{
		for (var i=0,len=arr.length; i<len; i++)
		{
			if (fn(arr[i])) return i;
		}
		return -1;
	},
	/* return array of elements for which FN(ARR[i]) is true */
	arrayOfMatched: function(fn, arr)
	{
		matched = [];
		for (var i=0,len=arr.length; i<len; i++)
		{
			if (fn(arr[i])) matched.push(arr[i])
		}
		return matched;
	},
	/* flattens multi-dimentional arrays into simple arrays */
	flatten: function(arr)
	{
		flt = [];
		for (var i=0,len=arr.length; i<len; i++)
		{
			if (typeof arr[i] == 'object' && arr.length) {
				flt.concat(Punbb.flatten(arr[i]))
				alert('length1!!'+ arr.length);
				//x.hasChildNodes()
			}
			else flt.push(arr[i])
		}
		return flt
	},
	/* check FORM's required (REQ_) fields */
	validateForm: function(form)
	{
		var elements = form.elements;
		var fn = function(x) { return x.name && x.name.indexOf('req_')==0 };
		var nodes = Punbb.arrayOfMatched(fn, elements);
		fn = function(x) { return /^\s*$/.test(x.value) };
		var empty = Punbb.find(fn, nodes);
		if (empty > -1)
		//if (Punbb.find(fn, nodes) > -1)
		{
			var n = document.getElementById('req-msg');
			Punbb.removeClass(n, 'frm-warn');
			var newlyAdded = Punbb.addClass(n, 'frm-error');
			if (!Punbb.onScreen(n))
			{
				n.scrollIntoView(); // method not in W3C DOM, but fully cross-browser?
				setTimeout(function(){Punbb.blink(n)}, 500);
			}
			else if (!newlyAdded) Punbb.blink(n);
			if (Punbb.onScreen(nodes[empty])) nodes[empty].focus();
			return false;
		}
		return true;
	},
	/* attach form validation function to submit-type inputs */
	attachValidateForm: function()
	{
		var forms = document.forms;
		for (var i=0,len=forms.length; i<len; i++)
		{
			var elements = forms[i].elements;
			var fn = function(x) { return x.name && x.name.indexOf('req_')==0 };
			if (Punbb.find(fn, elements) > -1)
			{
				fn = function(x) { return x.type && (x.type=='submit' && x.name!='cancel') };
				var nodes = Punbb.arrayOfMatched(fn, elements)
				var formRef = forms[i];
				fn = function() { return Punbb.validateForm(formRef) };
				//TODO: look at passing array of node refs instead of forum ref
				//fn = function() { return Punbb.checkReq(required.slice(0)) };
				nodes = Punbb.map(function(x){x.onclick=fn}, nodes);
			}
		}
	},
	attachWindowOpen: function()
	{
		if (!document.getElementsByTagName) return;
		var nodes = document.getElementsByTagName('a');
		for (var i=0; i<nodes.length; i++)
		{
			if (Punbb.hasClass(nodes[i], 'exthelp')) // || nodes[i].getAttribute('rel') == 'external')
				nodes[i].onclick = function() { window.open(this.href); return false; };
		}
	},
	autoFocus: function()
	{
		var nodes = document.getElementById('afocus');
		if (!nodes || window.location.hash.replace(/#/g,'')) return;
		nodes = nodes.all ? nodes.all : nodes.getElementsByTagName('*');
		// TODO: make sure line above gets nodes in display-order across browsers
		var fn = function(x) { return x.tagName.toUpperCase()=='TEXTAREA' || (x.tagName.toUpperCase()=='INPUT' && (x.type=='text') || (x.type=='password')) };
		var n = Punbb.find(fn, nodes);
		if (n > -1) nodes[n].focus();
	}
}
Punbb.addLoadEvent(Punbb.attachValidateForm);
Punbb.addLoadEvent(Punbb.attachWindowOpen);
Punbb.addLoadEvent(Punbb.autoFocus);

/* A handful of functions in this script have been released into the Public
   Domain by Shawn Brown or other authors. Although I, Shawn Brown, do not
   believe that it is legally necessary to note which parts of a Copyrighted
   work are based on Public Domain content, a list of the Public Domain
   code (functions and methods) contained in this file is included below:
   
   * addLoadEvent: Released into the Public Domain by Shawn Brown and
        based on Simon Willison's Public Domain function of the same name.
   * hasClass, addClass & removeClass: Released into the Public Domain
        by Shawn Brown.
   * onScreen: Released into the Public Domain by Shawn Brown and based,
        in-part, on Peter Paul-Koch's Public Domain node-position functions.
   * map, find, arrayOfMatched & flatten: These basic functional methods
        have been released into the Public Domain by Shawn Brown.

   It is entirely possible that, in the future, someone may contribute code
   that is in the Public Domain but not note it as such. This should not be
   a problem, but one should keep in mind that the list provided here is known
   to be complete and accurate only up until 24-JUNE-2007.
*/