// -------------------------------------------------------------------
// Check for valid email address                              
// -------------------------------------------------------------------
function emailCheck (emailStr) {
var checkTLD=1;
var knownDomsPat=/^(aero|ag|arpa|asia|at|be|biz|bz|ca|cc|cn|co.in|co.nz|co.uk|com|com.ag|com.bz|com.cn|com.mx|com.tw|coop|de|edu|eu|firm.in|fm|gen.in|gov|gs|idv.tw|in|ind.in|info|int|jobs|jp|me|me.uk|mil|mobi|ms|museum|mx|name|net|net.ag|net.bz|net.cn|net.in|net.nz|nu|org|org.ag|org.cn|org.in|org.nz|org.tw|org.uk|pro|tc|tv|tw|us|vg|ws)$/;
var emailPat=/^(.+)@(.+)$/;
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 +")*$");
var matchArray=emailStr.match(emailPat);
if (matchArray==null) {
alert("Email address seems incorrect (check @ and .'s)");
return false;
}
var user=matchArray[1];
var domain=matchArray[2];
for (i=0; i<user.length; i++) {
if (user.charCodeAt(i)>127) {
alert("Ths username contains invalid characters.");
return false;
   }
}
for (i=0; i<domain.length; i++) {
if (domain.charCodeAt(i)>127) {
alert("Ths domain name contains invalid characters.");
return false;
   }
}
if (user.match(userPat)==null) {
alert("The username doesn't seem to be valid.");
return false;
}
var IPArray=domain.match(ipDomainPat);
if (IPArray!=null) {
for (var i=1;i<=4;i++) {
if (IPArray[i]>255) {
alert("Destination IP address is invalid!");
return false;
   }
}
return true;
} 
var atomPat=new RegExp("^" + atom + "$");
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.");
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.");
return false;
}
if (len<2) {
alert("This address is missing a hostname!");
return false;
}
return true;
}