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. */
			alert("Email address seems incorrect (check @ and .'s)")
			return false
	}
	var user=matchArray[1]
	var domain=matchArray[2]

	// See if "user" is valid 
	if (user.match(userPat)==null) {
			// user is not valid
			alert("The username doesn't seem to be 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) {
							alert("Destination IP address is invalid!")
					return false
					}
			}
			return true
	}

	// Domain is symbolic name
	var domainArray=domain.match(domainPat)
	if (domainArray==null) {
			alert("The domain name doesn't seem to be valid.")
			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>3) {
		// the address must end in a two letter or three letter word.
		alert("The address must end in a three-letter domain, or two letter country.")
		return false
	}

	// Make sure there's a host name preceding the domain.
	if (len<2) {
		var errStr="This address is missing a hostname!"
		alert(errStr)
		return false
	}

	// If we've gotten this far, everything's valid!
	return true;
}

function submitForm(theForm)
{
	var OK = true
	if (theForm.email.value=='')
	{
		alert('Put in an email address, but the rest can remain blank, except for the feedback details.');
		theForm.email.focus();
		return(false);
	}
	else
	{
		if (!emailCheck(theForm.email.value))
		{
			return(false);
		}
	}

	if (theForm.description.value=='')
	{
		alert('Put in some Feedback details.');
		theForm.description.focus();
		return(false);
	}
		
	if (OK) 
	{
		alert('Thank You!\n\nWe will get back to you as soon as possible.');
		return(true);
	}

}