/* This script has to be referenced somewhere in your web page. I recomend 
   placing this script snippet just after Google Analytics tracking code.

	</script src="adsenseClicksTracker.js" type="text/javascript"></script>	
*/
var analyticsTag = '/asclick';

// init adsense click tracking after docuement load...
attachOnloadEvent(adsenseTrackerInit);

// helper global variables
var adsenseTrackerActive = false;
var adsenseTrackerUnit = '';

function adsenseTrackerInit() {
	var pageHasAdsense = false;
	var el = document.getElementsByTagName("iframe");
	for (var i=0; i<el.length; i++) {
		if (el[i].src.indexOf('googlesyndication.com') > -1) {
			pageHasAdsense = true;

			el[i].onmouseover = adsenseTrackerActivate;
			el[i].onmouseout = adsenseTrackerDeActivate;
		}
	}

	if (pageHasAdsense) {
		if (typeof window.attachEvent != 'undefined') {
			// this works for IE
			window.attachEvent('onbeforeunload', adsenseTrackerCheckClick);
		} else if (typeof window.addEventListener != 'undefined') {
			// this works for firefox
			window.addEventListener('beforeunload', adsenseTrackerCheckClick, false);
		}
	}
}

function adsenseTrackerCheckClick() {
	if (adsenseTrackerActive) {
		var reportedUrl = analyticsTag;

		if (adsenseTrackerUnit != '') {
			reportedUrl += '/'+ escape(adsenseTrackerUnit);
		}

		// check for ad Url/AsLinks text (is disabled in Firefox by default)
		if (window.status) {
			var adsenseClickedAd = '';

			if (window.status.substring(0, 6) == 'go to ') {
				adsenseClickedAd = window.status.substring(6);
			} else if (window.status.substring(0, 15) == 'View ads about ') {
				adsenseClickedAd = window.status.substring(15);
			} else if (window.status != '') {
				// universal window.status reporting
				// ad support for your language here...
				adsenseClickedAd = window.status;
			}
			if (adsenseClickedAd != '') {
				reportedUrl += '/'+ escape(adsenseClickedAd);
			}
		}

		// this could be replaced with other tracking sw...
		reportToGoogleAnalytics(reportedUrl)
	}
}

// when moving mouse to adsense frame, activate click tracking for current ad unit...
function adsenseTrackerActivate() {
	adsenseTrackerUnit = '';

	if (this.parentNode) {
		// check for custom asc_ adsense element id
		if (this.parentNode.id.substring(0, 4) == 'asc_') {
			adsenseTrackerUnit = this.parentNode.id.substring(4);
		}
	}
	if (adsenseTrackerUnit == '') {
		// decode format parameter from adsense ads url
		var url = this.src;
		var startIndex = url.indexOf('format=');
		if (startIndex >= 0) {
			var lastIndex = url.indexOf('&', startIndex);
			adsenseTrackerUnit = lastIndex >= 0 ? url.substring(startIndex + 7, lastIndex) : url.substring(startIndex + 7);
		}
	}
	adsenseTrackerActive = true;
}

// when moving mouse out of adsense frame, deactivate click tracking...
function adsenseTrackerDeActivate() {
	adsenseTrackerUnit = '';
	adsenseTrackerActive = false;
}

// report click to google Analytics
function reportToGoogleAnalytics(reportedUrl) {
	if (typeof urchinTracker == 'function') {
		urchinTracker(reportedUrl);
	}
}

// attach func function to window onload event (crossbrowser compatible)
function attachOnloadEvent(func) {
	if(typeof window.addEventListener != 'undefined') {
		// moz, saf1.2, ow5b6.1
		window.addEventListener('load', func, false);
	} else if (typeof document.addEventListener != 'undefined') {
		// MSN/OSX, op7.50, saf1.2, ow5b6.1
		document.addEventListener('load', func, false);
	} else if (typeof window.attachEvent != 'undefined') {
		// ie5.0w, ie5.5w, ie6w
		window.attachEvent('onload', func);
	} else {
		// all other browsers
		if (typeof window.onload == 'function') {
			var oldonload = onload;
			window.onload = function() {
				oldonload();
				func();
			};
		} else {
				window.onload = func;
		}
	}
}