Chapter 6: Beginning JavaScript
Controlling Data Entry Using Form Fields
Creating 'Encoded' Name & Value Pairs
You are here: irt.org | Articles | JavaScript | Form | Addressing Form Field Validation with Regular Expressions and JavaScript 1.2 [ previous next ]
Published on: Sunday 16th November 1997 By: Jason Nugent
<html>
<head>
<title>Regular Expressions for Form Field Validation</title>
<script language="JavaScript"><!--
function isEmail(string) {
if (!string) return false;
var iChars = "*|,\":<>[]{}`\';()&$#%";
for (var i = 0; i < string.length; i++) {
if (iChars.indexOf(string.charAt(i)) != -1)
return false;
}
return true;
}
function isProper(string) {
if (!string) return false;
var iChars = "*|,\":<>[]{}`\';()@&$#%";
for (var i = 0; i < string.length; i++) {
if (iChars.indexOf(string.charAt(i)) != -1)
return false;
}
return true;
}
function isReady(form) {
if (isEmail(form.address.value) == false) {
alert("Please enter a valid email address.");
form.address.focus();
return false;
}
if (isProper(form.username.value) == false) {
alert("Please enter a valid username.");
form.username.focus();
return false;
}
return true;
}
//--></script>
<script language="JavaScript1.2">
function isEmail(string) {
if (string.search(/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/) != -1)
return true;
else
return false;
}
function isProper(string) {
if (string.search(/^\w+( \w+)?$/) != -1)
return true;
else
return false;
}
//--></script>
</head>
<body>
<form name="form_name" onSubmit="return isReady(this)">
<table cellpadding=0 cellspacing=5 border=0><tr>
<td align="left">Your Name:</td><td align="left"><input type="text" name="username"></td>
</tr><tr>
<td align="left">Your Email Address:</td><td align="left"><input type="text" name="address"></td>
</tr><tr>
<td><input type="submit" value="Submit"></td>
</tr></table>
</form>
</body>
</html>Chapter 6: Beginning JavaScript
Controlling Data Entry Using Form Fields
Creating 'Encoded' Name & Value Pairs