Jiyl Jiyl - 4 months ago 13
HTML Question

Email validation function error on javascript

My email verfication doesn't seem to be working quite right -
it excepts the 'ffhjisf' isn't a valid email
and that "" empty field needs data,
but for some reason see a valid email as an error.
Please could you help me amend my email address check function?

Javascript

function checkForm(){

if (document.getElementById("fname").value == "" ) {
document.getElementById("errfname").style.display = "inline";
document.getElementById("errfname").style.visibility = "visible";
}

if (document.getElementById("fname").value.length < 2 ) { // and needs to be only letter and/or one hyphen
document.getElementById("errfname1").style.display = "inline";
document.getElementById("errfname1").style.visibility = "visible";
}

if (document.getElementById("sname").value == "" ) {
document.getElementById("errsname").style.display = "inline";
document.getElementById("errsname").style.visibility = "visible";
}

if (document.getElementById("sname").value.length < 2 ) { // just letters like first name (fname)
document.getElementById("errsname1").style.display = "inline";
document.getElementById("errsname1").style.visibility = "visible";
}

if (document.getElementById("title").value == "Please select" ) {
document.getElementById("errtitle").style.display = "inline";
document.getElementById("errtitle").style.visibility = "visible";
}

if (document.getElementById("HANo").value == "" ) {
document.getElementById("errHANo").style.display = "inline";
document.getElementById("errHANo").style.visibility = "visible";
}

if (document.getElementById("HANo").value.length != 6 ) { // and needs to be a number
document.getElementById("errHANo2").style.display = "inline";
document.getElementById("errHANo2").style.visibility = "visible";
}

if (document.getElementById("email").value == "" ) {
document.getElementById("erremail").style.display = "inline";
document.getElementById("erremail").style.visibility = "visible";
}

if (document.getElementById("email").value.length > 0 ) {
if(checkEmail())
{
document.getElementById("erremail").style.display = "inline";
document.getElementById("erremail").style.visibility = "visible";
}
}

if (document.getElementById("telno").value.length > 11 )
{ // and needs to be a number
document.getElementById("errtelno").style.display = "inline";
document.getElementById("errtelno").style.visibility = "visible";
}
}

function checkEmail(){
var email = document.getElementById('email');
var emailRegEx = /[-\w.]+@([A-z0-9][-A-z0-9]+\.)+[A-z]{2,4}/;

if (!emailRegEx.test(email.value))
{
document.getElementById("erremail2").style.display="inline";
document.getElementById("erremail2").style.visibility = "visible";
return false;
} else {
return true;
}
}


and html page

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>RATool</title>
<link rel="stylesheet" type="text/css" href="cfcss.css">
<script src="cf.js"></script>
</head>
<body>
<h1> Zedland Health Authority </h1>
<h2> Contact Form </h2>
<fieldset>
<label for="fname">First Name:</label>
<input name="fname" id="fname" class="formfield" type="text">
<span id="errfname" class="error">*This is required</span>
<span id="errfname1" class="error">*Name fields must have more than one character, and do not contain numbers
or other non-allowed alphabetic characters. The only character the last name
field should legitimately contain is a hyphen (e.g. Whittaker-Jones).</span>
<span id="errfname2" class="error">*This can only contain alphabetic numbers and one hyphen</span>
<br>
<label for="sname">Surname:</label>
<input name="sname" id="sname" class="formfield" type="text">
<span id="errsname" class="error">*This is required</span>
<span id="errsname1" class="error">*Name fields must have more than one character, and do not contain numbers
or other non-allowed alphabetic characters. The only character the last name
field should legitimately contain is a hyphen (e.g. Whittaker-Jones).</span>
<span id="errsname2" class="error">*This can only contain alphabetic numbers and one hyphen</span>
<br>
<label for="title">Title: </label>
<select name="title" id="title">
<option value="Please select">Please select</option>
<option value="Mr.">Mr.</option>
<option value="Ms.">Ms.</option>
<option value="Mrs.">Mrs.</option>
<option value="Miss.">Miss.</option>
<option value="Master.">Master.</option>
</select>
<span id="errtitle" class="error">*This is required</span>
<br>
<br>
<label for="HANo">Health Authority Number:</label>
<input name="HANo" id="HANo" class="formfield"type="text">
<span id="errHANo" class="error">*This is required</span>
<span id="errHANo2" class="error">* Numbers are in the form of a six-digit integer prefixed with the letters
ZHA (e.g. ZHA346783)</span>
<br>
<br>
<label for="email">Email:</label>
<input name="email" id="email" class="formfield"type="text">
<span id="erremail" class="error">*This is required</span>
<span id="erremail2" class="error">*Please enter a valid email</span>
<br>
<br>
<label for="telno">Telephone Number:</label>
<input name="telno" id="telno" class="formfield" type="text">
<span id="errtelno" class="error">* If a telephone number is entered, then it should contain only numbers, not
letters, or other disallowed characters. A valid Zedland telephone number has
11 digits (no spaces)</span>
<br>
<button onclick="checkForm()">Submit</button>
</fieldset>
</body>
</html>

Answer

Your checkEmail() function returns true with valid emails. However, with a valid email, this gets executed in your code:

if(checkEmail())
{
    document.getElementById("erremail").style.display = "inline";
    document.getElementById("erremail").style.visibility = "visible";
}

which is the opposite of what you would expect. Instead, set the error message as visible when !checkEmail().

Also, you should anchor your expression to ^ and $. Otherwise, it could match a substring such as "invalid email@foo.org here".

/^[-\w.]+@([A-z0-9][-A-z0-9]+\.)+[A-z]{2,4}$/

Code

function checkForm() {
    var mailInput = document.getElementById("email"),
        errEmail = document.getElementById("erremail"),
        errEmail2 = document.getElementById("erremail2");;
    if (mailInput.value == "") {  // Empty email
        errEmail.style.visibility = "visible";
        errEmail2.style.visibility = "hidden";
    } else {
        errEmail.style.visibility = "hidden";
        if (checkEmail(mailInput)) {  // Valid email
            errEmail2.style.visibility = "hidden";
        } else {             // Invalid email
            errEmail2.style.visibility = "visible";
        }
    }
}

function checkEmail(email) {
    var emailRegEx = /^[-\w.]+@([A-z0-9][-A-z0-9]+\.)+[A-z]{2,4}$/;
    return emailRegEx.test(email.value);
}
#erremail,
#erremail2 {
    display: inline;
    visibility: hidden;
}
<h1> Zedland Health Authority </h1>
<h2> Contact Form </h2>
<fieldset>
    <label for="email">Email:</label>
    <input name="email" id="email" class="formfield" type="text">
    <span id="erremail" class="error">*This is required</span>
    <span id="erremail2" class="error">*Please enter a valid email</span>
    <button onclick="checkForm()">Submit</button>
</fieldset>