function emailCheck(emailStr) {

var checkTLD=1;
var knownDomsPat=/^(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum)$/;
/*var checkNTLD=1;*/
/*var knownNatDomsPat=/^(af|al|dz|as|ad|ao|ai|aq|ag|ar|am|aw|au|at|az|bs|bh|bd|bb|by|be|bz|bj|bm|bt|bo|ba|bw|bv|br|io|bn|bg|bf|bi|kh|cm|ca|cv|ky|cf|td|cl|cn|cx|cc|co|km|cg|cd|ck|cr|ci|hr|cu|cy|cz|dk|dj|dm|do|tp|ec|eg|sv|gq|er|ee|et|fk|fo|fj|fi|fr|fx|gf|pf|tf|ga|gm|ge|de|gh|gi|gr|gl|gd|gp|gu|gt|gn|gw|gy|ht|hm|va|hn|hk|hu|is|in|id|ir|iq|ie|il|it|jm|jp|jo|kz|ke|ki|kp|kr|kw|kg|la|lv|lb|ls|lr|ly|li|lt|lu|mo|mk|mg|mw|my|mv|ml|mt|mh|mq|mr|mu|yt|mx|fm|md|mc|mn|ms|ma|mz|mm|na|nr|np|nl|an|nc|nz|ni|ne|ng|nu|nf|mp|no|om|pk|pw|pa|pg|py|pe|ph|pn|pl|pt|pr|qa|re|ro|ru|rw|kn|lc|vc|ws|sm|st|sa|sn|sc|sl|sg|sk|si|sb|so|za|gs|es|lk|sh|pm|sd|sr|sj|sz|se|ch|sy|tw|tj|tz|th|tg|tk|to|tt|tn|tr|tm|tc|tv|ug|ua|ae|gb|us|um|uy|uz|vu|ve|vn|vg|vi|wf|eh|ye|yu|zm|zw)$/;*/
var emailPat=/^(.+)@(.+)$/;
var specialChars="\\(\\)><@,;:\\\\\\\"\\.\\[\\]";
var validChars="\[^\\s" + specialChars + "\]";
var quotedUser="(\"[^\"]*\")";
var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/;
var atom=validChars + '+';
var word="(" + atom + "|" + quotedUser + ")";
var userPat=new RegExp("^" + word + "(\\." + word + ")*$");
var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$");
var matchArray=emailStr.match(emailPat);

if (matchArray==null) {
//alert("Email address seems incorrect (check @ and .'s)");
//alert("Indirizzo email non valido");
return false;
}
var user=matchArray[1];
var domain=matchArray[2];


for (i=0; i<user.length; i++) {
if (user.charCodeAt(i)>127) {
//alert("Tihs username contains invalid characters.");
//alert("Indirizzo email non valido (contiene caratteri non validi)");
return false;
   }
}
for (i=0; i<domain.length; i++) {
if (domain.charCodeAt(i)>127) {
//alert("Tihs domain name contains invalid characters.");
//alert("Indirizzo email non valido (contiene caratteri non validi)");
return false;
   }
}

if (user.match(userPat)==null) {
//alert("The username doesn't seem to be valid.");
//alert("Indirizzo email non valido");
return false;
}
var IPArray=domain.match(ipDomainPat);
if (IPArray!=null) {
for (var i=1;i<=4;i++) {
if (IPArray[i]>255) {
//alert("Destination IP address is invalid!");
//alert("Indirizzo email non valido");
return false;
   }
}
return true;
}

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.");
//alert("Indirizzo email non valido");
return false;
   }
}

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.");
//alert("Indirizzo email non valido");
return false;
}


if (len<2) {
//alert("This address is missing a hostname!");
//alert("Indirizzo email non valido");
return false;
}

return true;
}