function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

var leftNavDefault = false;
var leftNavLighthouse = new Array;
var leftNavOptions = new Array;

function defineImages() {

	// Lighthouse on and off
	leftNavLighthouse['off'] = newImage('images/leftnav_lighthouse.gif');
	leftNavLighthouse['on'] = newImage('images/leftnav_lighthouse_on.gif');

	// Left navigation option graphics
	leftNavOptions['off'] = newImage('images/leftnav_options.gif');
	leftNavOptions['profile'] = newImage('images/leftnav_options_profile.gif');
	leftNavOptions['process'] = newImage('images/leftnav_options_process.gif');
	leftNavOptions['services'] = newImage('images/leftnav_options_services.gif');
	leftNavOptions['professionals'] = newImage('images/leftnav_options_professionals.gif');
	leftNavOptions['library'] = newImage('images/leftnav_options_library.gif');
}

function initLeftNav( defaultOption ) {
	if (defaultOption) leftNavDefault = defaultOption;
	var is_nav6_1up = is_nav && parseFloat(is_minor) >= 6.1;
	var is_moz1_2up = is_moz && parseFloat(is_minor) >= 1.2;
	var is_ie5macup = is_ie5up && is_mac;
	if (is_nav6_1up || is_moz1_2up || is_ie5macup || is_opera5up || is_konq) {
		document.getElementById('navigation').style.position = 'fixed';
		if (document.getElementById('quote')) document.getElementById('quote').style.position = 'fixed';
	} else if (is_ie4up) {
		window.onscroll = setLeftNav;
		window.onresize = setLeftNav;
	}
	defineImages();
	if (leftNavDefault) optionOver(leftNavDefault);
}

function optionOver(option) {
	if (!leftNavOptions[option]) return false;
	document.getElementById('lighthouse').src = leftNavLighthouse['on'].src;
	document.getElementById('options').src = leftNavOptions[option].src;
}

function optionOut(option) {
	if (leftNavDefault) {
		document.getElementById('lighthouse').src = leftNavLighthouse['on'].src;
		document.getElementById('options').src = leftNavOptions[leftNavDefault].src;		
	} else {
		document.getElementById('lighthouse').src = leftNavLighthouse['off'].src;
		document.getElementById('options').src = leftNavOptions['off'].src;
	}
}

function setLeftNav() {
	var navTop = document.body.scrollTop;
	var quoteTop = document.body.scrollTop + 300;
	document.getElementById('navigation').style.top = navTop;
	if (document.getElementById('quote')) document.getElementById('quote').style.top = quoteTop;
}