function validateEmail(emailStr) {

	//this function validates email addresses
	//added by E.V.

	var errMsg;
	var myStr;
	errMsg = "";
 	//alert(emailStr);
 	var checkTLD=1;  /* This 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 knownDomsPat=/^(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum)$/i;  /* Is the list of known TLDs that an e-mail address must end with. */
 	var emailPat=/^(.+)@(.+)$/;  /*This  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 specialChars="\\(\\)><@,;:\\\\\\\"\\.\\[\\]!#$%&*?=~";  /* This string represents the pattern for matching all special characters.  We don't want to allow special characters in the address. These characters include ( ) < > @ , ; : \ " . [ ] */
	var validChars="\[^\\s" + specialChars + "\]";  /* This string represents the range of characters allowed in a username or domainname.  It really states which chars aren't allowed.*/
	var quotedUser="(\"[^\"]*\")";  /* This 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 ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/;  /* This pattern applies for domains that are IP addresses, rather than symbolic names.  E.g. joe@[123.124.233.4] is a legal e-mail address. NOTE: The square brackets are required. */
 	var atom=validChars + '+';  /* This string represents an atom (basically a series of non-special characters.) */
 	var word="(" + atom + "|" + quotedUser + ")"; /* This string represents one word in the typical username. For example, in john.doe@somewhere.com, john and doe are words. Basically, a word is either an atom or quoted string. */
 	var userPat=new RegExp("^" + word + "(\\." + word + ")*$");  // This pattern describes the structure of the user
 	var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$");  /* The following pattern describes the structure of a normal symbolic domain, as opposed to ipDomainPat, shown above. */
 	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;
		}
	return true;
}