function emailCheck (emailStr) {

var checkTLD = 1;
var knownDomsPat = /^(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum)$/;
var emailPat = /^(.+)@(.+)$/;
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("Penulisan Email ada kesalahan    ");
return false;
}
var user = matchArray[1];
var domain = matchArray[2];


for (i=0; i<user.length; i++) {
if (user.charCodeAt(i)>127) {
alert("Nama user Email tidak valid    ");
return false;
   }
}
for (i=0; i<domain.length; i++) {
if (domain.charCodeAt(i)>127) {
alert("Nama domain Email tidak valid    ");
return false;
   }
}


if (user.match(userPat) == null) {

alert("Nama user Email tidak valid    ");
return false;
}


var IPArray=domain.match(ipDomainPat);
if (IPArray!=null) {


for (var i=1;i<=4;i++) {
if (IPArray[i]>255) {
alert("Nama Domain Email tidak valid");
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("Nama domain Email tidak valid.");
return false;
   }
}


if (checkTLD && domArr[domArr.length-1].length!=2 && 
domArr[domArr.length-1].search(knownDomsPat)==-1) {
alert("Nama ekstensi Email salah    ");
return false;
}


if (len<2) {
alert("Nama Host Email tidak ada");
return false;
}

return true;
}