function handleEnter (field, event) {
	var keyCode = event.keyCode ? event.keyCode : event.which ? event.which : event.charCode;
	if (keyCode == 13 || keyCode == 3) {
		return false;
	}
	else
	return true;
}

function emailCheck (emailStr) {
	/* The following pattern is used to check if the entered e-mail address
	fits the user@domain format.  It also is used to separate the username
	from the domain. */
	var emailPat=/^(.+)@(.+)$/;
	/* The following string represents the pattern for matching all special
	characters.  We don't want to allow special characters in the address.
	These characters include ( ) < > @ , ; : \ " . [ ]    */
	var specialChars="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]"
	/* The following string represents the range of characters allowed in a
	username or domainname.  It really states which chars aren't allowed. */
	var validChars="\[^\\s" + specialChars + "\]";
	/* The following pattern applies if the "user" is a quoted string (in
	which case, there are no rules about which characters are allowed
	and which aren't; anything goes).  E.g. "jiminy cricket"@disney.com
	is a legal e-mail address. */
	var quotedUser="(\"[^\"]*\")";
	/* The following pattern applies for domains that are IP addresses,
	rather than symbolic names.  E.g. joe@[123.124.233.4] is a legal
	e-mail address. NOTE: The square brackets are required. */
	var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/;
	/* The following string represents an atom (basically a series of
	non-special characters.) */
	var atom=validChars + '+';
	/* The following string represents one word in the typical username.
	For example, in john.doe@somewhere.com, john and doe are words.
	Basically, a word is either an atom or quoted string. */
	var word="(" + atom + "|" + quotedUser + ")";
	// The following pattern describes the structure of the user
	var userPat=new RegExp("^" + word + "(\\." + word + ")*$");
	/* The following pattern describes the structure of a normal symbolic
	domain, as opposed to ipDomainPat, shown above. */
	var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$");


	/* Finally, let's start trying to figure out if the supplied address is
	valid. */

	/* Begin with the coarse pattern to simply break up user@domain into
	different pieces that are easy to analyze. */
	var matchArray=emailStr.match(emailPat);
	if (matchArray==null) {
		/* Too many/few @'s or something; basically, this address doesn't
		even fit the general mould of a valid e-mail address. */
		return false;
	}
	var user=matchArray[1];
	var domain=matchArray[2];

	// See if "user" is valid
	if (user.match(userPat)==null) {
		// user is not valid
		return false;
	}

	/* if the e-mail address is at an IP address (as opposed to a symbolic
	host name) make sure the IP address is valid. */
	var IPArray=domain.match(ipDomainPat);
	if (IPArray!=null) {
		// this is an IP address
		for (var i=1;i<=4;i++) {
			if (IPArray[i]>255) {
				return false;
			}
		}
		return true;
	}

	// Domain is symbolic name
	var domainArray=domain.match(domainPat);
	if (domainArray==null) {
		return false;
	}

	/* domain name seems valid, but now make sure that it ends in a
	three-letter word (like com, edu, gov) or a two-letter word,
	representing country (uk, nl), and that there's a hostname preceding
	the domain or country. */

	/* Now we need to break up the domain to get a count of how many atoms
	it consists of. */
	var atomPat=new RegExp(atom,"g");
	var domArr=domain.match(atomPat);
	var len=domArr.length;
	if (domArr[domArr.length-1].length<2 ||	domArr[domArr.length-1].length>4) {
		// the address must end in a two letter or three letter word.
		return false;
	}

	// Make sure there's a host name preceding the domain.
	if (len<2) {
		return false;
	}
	// If we've gotten this far, everything's valid!
	return true;
}

createNotes=function(){
	// gets all <a> elements
	spans=document.getElementsByTagName('span');
	// iterates over all <a> elements
	for(i=0;i<spans.length;i++){
		// assigns mouse event handlers to <a> elements with class name "special"
		if(/\bspecial\b/.test(spans[i].className)){
			// shows note element when mouse is over
			spans[i].onmousemove=function(evt){
				// gets corresponding note element id
				var id=this.id.replace(/span/,'note');
				note=document.getElementById(id);
				// assigns X,Y mouse coordinates to note element
				//note.style.left=this.event.clientX;
				//note.style.top=this.event.clientY;
				note.style.top=(evt.pageY - 120 ) +"px";
				note.style.left=(evt.pageX + 5 ) +"px";
				// makes note element visible
				note.style.visibility='visible';
			}
			// hides note element when mouse is out
			spans[i].onmouseout=hideNote=function(){
				// gets corresponding id for note element
				var id=this.id.replace(/span/,'note');
				note=document.getElementById(id);
				// hides note element
				note.style.visibility='hidden';
			}
		}
	}
}