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("Invalid e-mail address. (Please check for @ 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;
}

function checkForm(f){
r = false;
if (f.txFirst.value == '') {
	f.txFirst.focus();
	alert('FIRST NAME required.');
} else if (f.txLast.value == '') {
	f.txLast.focus();
	alert('LAST NAME required.');
} else if ((f.txEmail.value == '')||(f.txEmail.length <= 7)) {
	f.txEmail.focus();
	alert('E-MAIL ADDRESS is required.');
} else if (emailCheck(f.txEmail.value)==false) {
	f.txEmail.focus();
	alert('E-MAIL ADDRESS is invalid.');
} else if (f.txSubject.value == '') {
	f.txSubject.focus();
	alert('SUBJECT required.');
} else if (f.txMessage.length <= 5) {
	f.txMessage.focus();
	alert('Invaid MESSAGE.');
} else { 
    r = true;
}
return r;
}