/**
 * The tab is clicked and marked for display.
 */
function showTab(tab) {
	setRandomBannerImage();

	// set tabs to default
	document.getElementById('tabOpinio').className = 'inactive';
	document.getElementById('tabProbe').className = 'inactive';
	document.getElementById('tabEasyCharts').className = 'inactive';
	lostFocus(document.getElementById('tabOpinio'));
	lostFocus(document.getElementById('tabProbe'));
	lostFocus(document.getElementById('tabEasyCharts'));

	// display the correct content
	if (tab.id == 'tabOpinio') {
		document.getElementById('topRightLogo').className = 'opinioLogo';
		document.getElementById('opinioContent').className = 'display';
		document.getElementById('probeContent').className = 'hide';
		document.getElementById('chartContent').className = 'hide';
		tab.className = 'opinioActive';
	}
	else if (tab.id == 'tabProbe') {
		document.getElementById('topRightLogo').className = 'probeLogo';
		document.getElementById('opinioContent').className = 'hide';
		document.getElementById('probeContent').className = 'display';
		document.getElementById('chartContent').className = 'hide';
		tab.className = 'probeActive';
	}
	else if (tab.id == 'tabEasyCharts') {
		document.getElementById('topRightLogo').className = 'easychartsLogo';
		document.getElementById('opinioContent').className = 'hide';
		document.getElementById('probeContent').className = 'hide';
		document.getElementById('chartContent').className = 'display';
		tab.className = 'chartActive';
	}
}

/**
 * The mouse moves across the tab, highlight it.
 */
function gotFocus(tab) {
	tab.style.opacity = '0.8';
}

/**
 * The mouse moves away from the tab, remove the highligh.
 */
function lostFocus(tab) {
	if (tab.className != 'active') {
		tab.style.opacity = '1.0';
	}
}

/**
 * Sets the content based on the referrer.
 */
function setContent(referrer) {
	// set tabs to default
	document.getElementById('tabOpinio').className = 'inactive';
	document.getElementById('tabProbe').className = 'inactive';
	document.getElementById('tabEasyCharts').className = 'inactive';
	lostFocus(document.getElementById('tabOpinio'));
	lostFocus(document.getElementById('tabProbe'));
	lostFocus(document.getElementById('tabEasyCharts'));

	// display the correct content
	if (referrer && referrer.indexOf('probe') >= 0) {
		document.getElementById('tabProbe').className = 'probeActive';
		document.getElementById('topRightLogo').className = 'probeLogo';
		document.getElementById('opinioContent').className = 'hide';
		document.getElementById('probeContent').className = 'display';
		document.getElementById('chartContent').className = 'hide';
	}
	else if (referrer && referrer.indexOf('easycharts') >= 0) {
		document.getElementById('tabEasyCharts').className = 'chartActive';
		document.getElementById('topRightLogo').className = 'easychartsLogo';
		document.getElementById('opinioContent').className = 'hide';
		document.getElementById('probeContent').className = 'hide';
		document.getElementById('chartContent').className = 'display';
	}
	else {
		document.getElementById('tabOpinio').className = 'opinioActive';
		document.getElementById('topRightLogo').className = 'opinioLogo';
		document.getElementById('opinioContent').className = 'display';
		document.getElementById('probeContent').className = 'hide';
		document.getElementById('chartContent').className = 'hide';
	}
}