function showpic(num,imgel,numPhotos) {
      for (i=0; i < numPhotos; i++) {                      
          if (i != num) {
              hidediv(imgel + i);
          } else {
              showdiv(imgel + i);
          }
      }
  }
  function showdiv(divname) {
      document.getElementById(divname).style.visibility='visible';                  
      document.getElementById(divname).style.display='block';
  }
  function hidediv(divname) {                  
      document.getElementById(divname).style.visibility='hidden';
      document.getElementById(divname).style.display='none';
  }
  function swapdivs(divname1,divname2) {
      hidediv(divname2);
      showdiv(divname1);
  }
  function nextpic(imgel,picNum,numPhotos) {
      if(picNum < (numPhotos -1)) {
          showpic(++picNum,imgel,numPhotos);
      }
  }
  function previouspic(imgel,picNum,numPhotos) {
      if(picNum > 0) {
          showpic(--picNum,imgel,numPhotos);
      }
  }
<!-- V1.1.3: Sandeep V. Tamhankar (stamhankar@hotmail.com) -->
<!-- Original:  Sandeep V. Tamhankar (stamhankar@hotmail.com) -->
function isEmailValid (emailStr) {
	/* validation for required is not done here */
	if(emailStr == '') {
		return true;
	}

	/* 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. */

		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) {
			return false;
		}
	}
	for (i=0; i<domain.length; i++) {
		if (domain.charCodeAt(i)>127) {
			return false;
		}
	}

	// 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.  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) {
			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) {
		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;
}