/* 1.1.2: Fixed a bug where trailing . in e-mail address was passing
            (the bug is actually in the weak regexp engine of the browser; I
            simplified the regexps to make it work).
   1.1.1: Removed restriction that countries must be preceded by a domain,
            so abc@host.uk is now legal.  However, there's still the 
            restriction that an address must end in a two or three letter
            word.
     1.1: Rewrote most of the function to conform more closely to RFC 822.
     1.0: Original
Changes:  Sandeep V. Tamhankar (stamhankar@hotmail.com)
This script and many more are available free online at
The JavaScript Source!! http://javascript.internet.com
*/
function emailCheck (emailStr) {
/* The following 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 emailPat=/^(.+)@(.+)$/
/* The following string represents the pattern for matching all special
   characters.  We don't want to allow special characters in the address. 
   These characters include ( ) < > @ , ; : \ " . [ ]    */
var specialChars="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]"
/* The following string represents the range of characters allowed in a 
   username or domainname.  It really states which chars aren't allowed. */
var validChars="\[^\\s" + specialChars + "\]"
/* The following 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 quotedUser="(\"[^\"]*\")"
/* The following 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 ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/
/* The following string represents an atom (basically a series of
   non-special characters.) */
var atom=validChars + '+'
/* The following string represents one word in the typical username.
   For example, in john.doe@somewhere.com, john and doe are words.
   Basically, a word is either an atom or quoted string. */
var word="(" + atom + "|" + quotedUser + ")"
// The following pattern describes the structure of the user
var userPat=new RegExp("^" + word + "(\\." + word + ")*$")
/* The following pattern describes the structure of a normal symbolic
   domain, as opposed to ipDomainPat, shown above. */
var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$")
/* Finally, let's start trying to figure out if the supplied address is valid. */
/* Begin with the coarse pattern to simply break up user@domain into different pieces that are easy to analyze. */
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. */
	alert("Errors in email address");
	return false
}
var user=matchArray[1]
var domain=matchArray[2]

// See if "user" is valid 
if (user.match(userPat)==null) {
    // user is not valid
    alert("Invalid email name")
    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) {
	        alert("Errors in email address");
		return false
	    }
    }
    return true
}

// Domain is symbolic name
var domainArray=domain.match(domainPat)
if (domainArray==null) {
	alert("Errors in email address")
	return false
}
/* domain name seems valid, but now make sure that it ends in a
   three-letter word (like com, edu, gov) or a two-letter word,
   representing country (uk, nl), and that there's a hostname preceding 
   the domain or country. */

/* Now we need to break up the domain to get a count of how many atoms
   it consists of. */
var atomPat=new RegExp(atom,"g")
var domArr=domain.match(atomPat)
var len=domArr.length
if (domArr[domArr.length-1].length<2 || 
    domArr[domArr.length-1].length>3) {
   // the address must end in a two letter or three letter word.
   alert("Errors in email address")
   return false
}

// Make sure there's a host name preceding the domain.
if (len<2) {
   alert("Errors in email address")
   return false
}
// If we've gotten this far, everything's valid!
return true;
}

/*My own code here*/
function Check(form)
{
	if( form.fname.value == "" ) {
		alert('Please Specify First Name!');
		form.fname.focus();
		return false;
	}
	if(form.fname.value.match(/[&<>]+/)){
		alert("Please remove Invalid characters from First Name (e.g. &  < >)");
		form.fname.focus();
		return(false);
	}
	if ( form.lname.value == "" ) {
		alert('Please Specify Last Name!');
		form.lname.focus();
		return false;
	}
	if(form.lname.value.match(/[&<>]+/)){
		alert("Please remove Invalid characters from Last Name (e.g. &  < >)");
		form.lname.focus();
		return(false);
	}
	if(form.url.value.match(/[&<>]+/)){
		alert("Please remove Invalid characters from URL (e.g. &  < >)");
		form.url.focus();
		return(false);
	}
	if (form.title.value == "") {
		alert('Please Specify Title.');
		form.title.focus();
		return false;
	}
	if(form.title.value.match(/[&<>]+/)){
		alert("Please remove Invalid characters from Title (e.g. &  < >)");
		form.title.focus();
		return(false);
	}
	if (form.comments.value == "") {
		alert('Please Specify Comments/Feedback.');
		form.comments.focus();
		return false;
	}
	if(form.comments.value.match(/[&<>]+/)){
		alert("Please remove Invalid characters from Comments/Feedback (e.g. &  < >)");
		form.comments.focus();
		return(false);
	}
	if(form.email.value==''){
		alert("Please Specify Email address");
		return false;
	}
	if(!emailCheck(form.email.value)){
		return false;
	}
	if(showok)alert("No errors");
	return false;
}
function validate(form) 
{
	if((form.username.value == "")){
		alert('Please Specify Username!');
		form.username.focus();
		return false;
	}
	if((form.username.value.match(/[^a-zA-Z0-9_]/))){
		alert("Username can contain only alphanumeric and underscore character");
		form.username.focus();
		return(false);
	}
	if(form.password.value == ""){
		alert('Please Specify Password.');
		form.password.focus();
		return false; 
	}
	if (form.password.value != form.pwd2.value){
		alert('Passwords do not match.');
		form.pwd2.value="";
		form.password.focus();
		form.password.select();
		return false;
	}
	if(form.firstname.value==""){
		alert('Please Specify Firstname!');
		form.firstname.focus();
		return false;
	}
	if(form.firstname.value.match(/[&<>]+/)){
		alert("Please remove Invalid characters from Firstname (e.g. &  < >)");
		form.firstname.focus();
		return(false);
	}
	if(form.lastname.value == "" ){
		alert('Please Specify Lastname!');
		form.lastname.focus();
		return false;
	}
	if(form.lastname.value.match(/[&<>]+/)){
		alert("Please remove Invalid characters from Lastname (e.g. &  < >)");
		form.lastname.focus();
		return(false);
	}
	if(isNaN(form.dob_year.value)||form.dob_year.value==""||form.dob_year.value <= 0 ){// || form.dob_year.value<1900 || form.dob_year.value>2000 ) 
		alert('Please Specify valid Year in Date of Birth!');
		form.dob_year.focus();
		return false;
	}
	if(!emailCheck (form.email.value) ){
		form.email.focus();
		return (false);
	}
	if(form.street.value==""){
		alert('Please Specify Street!');
		form.street.focus();
		return false;
	}
	if(form.street.value.match(/[&<>]+/)){
		alert("Please remove Invalid characters from Street (e.g. &  < >)");
		form.street.focus();
		return(false);
	}
	if(form.city.value == ""){
		alert('Please Specify City!');
		form.city.focus();
		return false;
	}
	if(form.city.value.match(/[&<>]+/)){
		alert("Please remove Invalid characters from City(e.g. &  < >)");
		form.city.focus();
		return(false);
	}
	if ( (form.state.selectedIndex == 0 ) && (form.other_state.value == "") ) {
		alert('Please Specify State!');
		form.state.focus();
		return false;
	}
	if(form.other_state.value.match(/[&<>]+/)){
		alert("Please remove Invalid characters from State(e.g. &  < >)");
		form.other_state.focus();
		return(false);
	}
	if ( form.zip_code.value == "" ) {
		alert('Please Specify Zip/Postal Code!');
		form.zip_code.focus();
		return false;
	}
	if(form.zip_code.value.match(/[&<>]+/)){
		alert("Please remove Invalid characters from Zip/Postal Code (e.g. &  < >)");
		form.zip_code.focus();
		return(false);
	}
	if( form.country.selectedIndex == 0 ) {
		alert('Please Choose a Country!');
		form.country.focus();
		return false;
	}
	return true;
}