/*************** button color changing for mailing list sign-up **********************/

function hoverItemOn(x) {
   x.style.backgroundColor = "#772121";
   x.style.color = "#EBEBEB";
}

function hoverItemOff(x) {
   x.style.backgroundColor = "#EBEBEB";
   x.style.color = "#772121";
}

/*************** window popup for gallery page ***************************************/

function open_popup_gallery(popurl) {
	var winpops=window.open(popurl,"","width=420,height=611,scrollbars=no,toolbar=no")
}

/*************** window popup for emailing an article ********************************/
function open_popup_mail(popurl) {
	var winpops=window.open(popurl,"","width=570,height=380,scrollbars=no,toolbar=no")
}

/*************** window popup for subject gallery page *******************************/

function open_popup_subject(popurl){
	var winpops=window.open(popurl,"","width=560,height=495,scrollbars=no,toolbar=no")
}

/*************** adding bookmark *****************************************************/

function addbookmark(bmurl, bmtitle) {
    if (document.all) {
		window.external.AddFavorite("http://"+location.host+bmurl,bmtitle)
	}
}

/*************** email address validation ********************************************/

function emailCheck (emailStr) {
	
	/* The following variable tells the rest of the function whether or not
	to verify that the address ends in a two-letter country or well-known
	TLD.  1 means check it, 0 means don't. */
	
	var checkTLD=1;
	
	/* The following is the list of known TLDs that an e-mail address must end with. */
	
	var knownDomsPat=/^(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum)$/;
	
	/* 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];
	
	// Start by checking that only basic ASCII characters are in the strings (0-127).
	
	for (i=0; i<user.length; i++) {
		if (user.charCodeAt(i)>127) {
			alert("Ths username contains invalid characters.");
			return false;
	   }
	}
	for (i=0; i<domain.length; i++) {
		if (domain.charCodeAt(i)>127) {
			alert("Ths domain name contains invalid characters.");
			return false;
	   }
	}
	
	// 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.  Check if it's valid.
	 
	var atomPat=new RegExp("^" + atom + "$");
	var domArr=domain.split(".");
	var len=domArr.length;
	for (i=0;i<len;i++) {
		if (domArr[i].search(atomPat)==-1) {
			alert("The domain name does not seem to be valid.");
			return false;
		}
	}

	/* domain name seems valid, but now make sure that it ends in a
	known top-level domain (like com, edu, gov) or a two-letter word,
	representing country (uk, nl), and that there's a hostname preceding 
	the domain or country. */
	
	if (checkTLD && domArr[domArr.length-1].length!=2 && 
	domArr[domArr.length-1].search(knownDomsPat)==-1) 
	{
		alert("The address must end in a well-known domain or two letter " + "country.");
		return false;
	}

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

	// If we've gotten this far, everything's valid!
	return true;
} /* end email address validation */