// swap(image string, on boolean)
// name pattern based on/off state swap function
// requires oldswapsrc

var oldswapsrc = new Array();  //required for swap()

function swap(image, on) {
    var img = document.images[image];
	if (on) {
        if (img.src != img.src.replace(/_off/gi, '_over')) {oldswapsrc[image] = img.src;}
		img.src = img.src.replace(/_off/gi, '_over');
	} else {
		if (oldswapsrc[image]) img.src = oldswapsrc[image];
	}
}
    
function changeClass(item, newclass) {
	var cell = document.getElementById(item);
	cell.className = newclass;
}

function preload() {
	args = preload.arguments;
	var preloaded = new Array();
	for (i=0;i<args.length;i++) {
		preloaded[i] = new Image();
		preloaded[i].src = args[i];
	}
}

function swapTabs(tab) {
	var tabs = new Array('most_popular', 'most_commented');
	var tab_bar = 'most_popular_tabs';
	var off_class = 'off';
	var list_suffix = '_list';
	
	for (i=0; i<tabs.length; i++) {
		if (tab == tabs[i]) {
			// first change tab class
			changeClass(tab_bar, tabs[i]);

			// now show new tab list
			changeClass(tabs[i]+list_suffix, '');
		} else {
			// hide old tab list
			changeClass(tabs[i]+list_suffix, off_class);
		}
	}
}


/*This script is courtesy of HTML Dog (http://www.htmldog.comarticles/suckerfish/dropdowns/
Authored by: Patrick Griffiths and Dan Webb */

sfHover = function() {
	var sfEls = document.getElementById("topnav").getElementsByTagName("li");
	for (var i=0; i<sfEls.length; i++) {
		sfEls[i].onmouseover=function() {
			this.className+=" sfhover";
		}
		sfEls[i].onmouseout=function() {
			this.className=this.className.replace(new RegExp(" sfhover\\b"), "");
		}
	}
}
if (window.attachEvent) window.attachEvent("onload", sfHover);