Email

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Email Address Validation

2. Obtain the Script

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Introduction Add to Your Page Spanish Version Multiple Destination

The first step in using this script is to select the code from the text box below (there is a highlight all button beneath it to make this easier) and copy it into a file called email.js.

// Email Validation Javascript
// copyright 23rd March 2003, by Stephen Chapman, Felgall Pty Ltd

// You have permission to copy and use this javascript provided that
// the content of the script is not changed in any way.

function validateEmail(addr,man,db) {
if (addr == '' && man) {
   if (db) alert('email address is mandatory');
   return false;
}
if (addr == '') return true;
var invalidChars = '\/\'\\ ";:?!()[]\{\}^|';
for (i=0; i<invalidChars.length; i++) {
   if (addr.indexOf(invalidChars.charAt(i),0) > -1) {
      if (db) alert('email address contains invalid characters');
      return false;
   }
}
for (i=0; i<addr.length; i++) {
   if (addr.charCodeAt(i)>127) {
      if (db) alert("email address contains non ascii characters.");
      return false;
   }
}

var atPos = addr.indexOf('@',0);
if (atPos == -1) {
   if (db) alert('email address must contain an @');
   return false;
}
if (atPos == 0) {
   if (db) alert('email address must not start with @');
   return false;
}
if (addr.indexOf('@', atPos + 1) > - 1) {
   if (db) alert('email address must contain only one @');
   return false;
}
if (addr.indexOf('.', atPos) == -1) {
   if (db) alert('email address must contain a period in the domain name');
   return false;
}
if (addr.indexOf('@.',0) != -1) {
   if (db) alert('period must not immediately follow @ in email address');
   return false;
}
if (addr.indexOf('.@',0) != -1){
   if (db) alert('period must not immediately precede @ in email address');
   return false;
}
if (addr.indexOf('..',0) != -1) {
   if (db) alert('two periods must not be adjacent in email address');
   return false;
}
var suffix = addr.substring(addr.lastIndexOf('.')+1);
if (suffix.length != 2 && suffix != 'com' && suffix != 'net' && suffix != 'org' && suffix != 'edu' && suffix != 'int' && suffix != 'mil' && suffix != 'gov' & suffix != 'arpa' && suffix != 'biz' && suffix != 'aero' && suffix != 'name' && suffix != 'coop' && suffix != 'info' && suffix != 'pro' && suffix != 'museum') {
   if (db) alert('invalid primary domain in email address');
   return false;
}
return true;
}

Now all that remains is to add the script to your page.

Sample Page
Obtain the Script | Add to Your Page
Spanish Version | Multiple Destinations

Note that the script and the description of how to use it are copied from the "Ask Felgall" website with the permission of the copyright owner.

Stephen Chapman

Guide since 2004

Stephen Chapman
JavaScript Guide

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