function WindowOnload(f) {
	var prev = window.onload;
	window.onload = function() { if (prev) prev(); f(); }
}


// Popup menus

var hMenus = new Array("left_nav");

function enableIEHover() {
	for (var m = 0; m < hMenus.length; m++) {
		menu = hMenus[m];
		var li = document.getElementById(menu+"_main").getElementsByTagName("li");
		for (var i = 0; i < li.length; i++) {
			if (li[i].className == menu+"_parent") {
				li[i].onmouseover = function() { this.className += " over"; }
				li[i].onmouseout = function() { this.className = menu+"_parent"; }
			}
		}
	}
}
WindowOnload(enableIEHover);


// Assign new classes to tags (e.g., table trs or tds) by passing
// base element ID and the tag identifier ("td").  The new class
// is appended as "id_tagN" where N is zero or one (MOD alt).

function alternateTags(id, tag, alt) {
	var tags = document.getElementById(id).getElementsByTagName(tag);
	for (i = 0; i < tags.length; i++)
		tags[i].className += ' ' + id + '_' + tag + (i % alt == 0 ? 1 : 0);
}