function checkMailingList(f) {
	var emailcheck = checkEmail(f.email.value);
        if(!emailcheck) {
                alert("Please enter valid email addresses.\n");
                return false;
        }
	f.submit();
        return true;
}

function checkSpotlight(f) {
	var requiredText = Array('Name','Age','Email');
	var requiredRadio = Array('Sex');
	var errors = '';
	for(r in requiredText) {
		var field = eval("document." + f + "." + requiredText[r].toLowerCase());
		if(!checkRequiredText(field.value)) {
			errors += "   " + requiredText[r] + " is required\n";
		}
	}
	for(r in requiredRadio) {
		var elt = eval("document." + f + "." + requiredRadio[r].toLowerCase());
		if(!checkRequiredRadio(elt)) {
			errors += "   " + requiredRadio[r] + " is required\n";
		}
	}
	if(!checkEmail(eval("document." + f + ".email.value"))) {
		errors += "   Enter a valid email address.\n";
	}
	if(errors.length > 0) {
		alert("Please correct the following errors:\n\n" + errors);
		return false;
	}
	return true;
}


function checkEmail(email) {
        var pattern = /^[a-z\'0-9]+([._-][a-z\'0-9]+)*@([-_a-z0-9]?([._-]?[a-z0-9]+))+\.[a-z]{2,}$/i;
        if(email.match(pattern)) {
		return true;
	}
	return false;
}

function checkRequiredText(fieldvalue) {
	for(i = 0; i < fieldvalue.length; i++) {
		var c = fieldvalue.charAt(i);
		if(c != ' ' && c != '\n' && c != '') return true;
	}
	return false;
}

function checkRequiredRadio(elt) {
	for(i = 0; i < elt.length; i++) {
		if(elt[i].checked == true) {
			return true;
		}
	}
	return false;
}

function checkQuickpoll(form,maxselections) {
	var errors = '';
	var f = form;
	var count = 0;
	question = 1;
	if(maxselections != 0) {
		for(var i = 0; i < f.elements.length; i++) {
			if(f.elements[i].checked == true) {
				count++;
			}
		}
		if(count > maxselections) {
			errors += 'Please select up to ' + maxselections + ' choices.';
		}
		count = 0;
	 
		if(errors.length > 0) {
			alert(errors);
			return false;
		}
	}
	return true;
}

function departmentSponsor(fileName, visible) {
	box = document.getElementById("sponsor_box");
	
	if(visible)
		box.style.display = "block";
	else
		box.style.display = "none";
	
	if(fileName)
		img = '<img src="/images/sponsors/' + fileName + '" />';
	else
		img = '';
	box.innerHTML = img;
}

// click tracking  code
function click_track(e) {
	var el;
	var url = "none";
	var urlprefix = "/cgi-bin/ntlinktrack.cgi?";
	var domain = window.location.hostname;
	var n;

	/* Get the event object */
	if(window.event) {
		e = window.event; // get IE event
		el = e.srcElement;
	} else {
		el = e.target;
	}
	n = el;

	if(n.parentNode != null) {
		while(n.parentNode != null && !(n.tagName == 'A' || n.tagName == 'a')) {
			n = n.parentNode;
		}
	}
	
	if(n.href != null)
		url = n.href;

	//* Make sure we're not dealing with a local link */
	if(url != "none" && url.indexOf(domain)  == -1) {
		/* Stop the normal link from being followed */
		if(e.stopPropogation) {
			e.stopPropogation();
		} else {
			e.cancelBubble = true;
		}		
		if(e.preventDefault)
			e.preventDefault();
		else
			e.returnValue = false;
		
		/* Follow a new link. also have path global to append */
		window.location.href = urlprefix + url;
	}
}

/* Start the event listeners
We're no longer using this. All ads are tracked with icadhub.com
if(document.addEventListener) {
	document.addEventListener("click",click_track,true);
} else if(document.attachEvent) {
	document.attachEvent("onclick", click_track);
} else {
	document.onclick = click_track;
}
*/