Error with form validation (javascript)

Question

I have the following HTML code:

<form name="Register" action="Register.aspx" method="post" runat="server" style="margin-top: 15px;" onsubmit="return validateProfile(FormName='Register');" >
  <p> Name* : <input id="FirstName" type="text" name="FirstName"/> </p>
<form>

And this JavaScript code:

function isEmpty(field) {       
  if (field == "" || field == null)
    return false;
}

function validateProfile(FormName) {
    var errFname = "";
    var Fname = document.forms[FormName]["FirstName"].value;
    alert(isEmpty(field=Fname));
    return false;
}

The problem here is that the validation doesn't work...

I want that if the field is empty there will be an alert message. The solution might be very simple, but I just start leran this validtion with javascript.

I have to used the isEmpty function in the code.

Your code works: jsfiddle.net/Uy2ha

jantimon
– jantimon

2013-05-14 10:09:54 +00:00
Commented May 14, 2013 at 10:09 — jantimon
– jantimon, Commented May 14, 2013 at 10:09

PSR · Accepted Answer · 2013-05-14 10:04:57Z

1

change

validateProfile(FormName='Register');

to

validateProfile('Register');

and

alert(isEmpty(field=Fname));

to

   alert(isEmpty(Fname));


function validateProfile(FormName) {
    var errFname = "";
    var Fname = document.forms[FormName]["FirstName"].value;
    return isEmpty(Fname);
}

answered May 14, 2013 at 10:04

PSR

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6 Comments

jantimon Over a year ago

This won't change much - will it?

jantimon Over a year ago

It isn't smart to do it but I can't see why it should cause errors

Nave Tseva Over a year ago

Hi, Thank you! But the problem now is that even if the field is empty after submit the form is submiting, how can I preven this?

PSR Over a year ago

can u explain clearly.What is after submit the form is submiting,

Nave Tseva Over a year ago

After click submit, I see the alert, but after closing the the alert, the form is submiting, even that the field is empty...

|

user2334807 · Accepted Answer · 2013-05-14 10:12:28Z

1

You should use the following code:

function validateProfile(FormName) {
        var errFname = "";
        var Fname = document.getElementById("FirstName").value;
        alert(isEmpty(Fname));
        return false;
}

You can use the id of textfield as you have given it. And change the form tag with code:

<form name="Register" action="Register.aspx" method="post" runat="server" style="margin-top: 15px;" onsubmit="return validateProfile('Register');" >

answered May 14, 2013 at 10:12

user2334807

Comments

shyam · Accepted Answer · 2013-05-14 10:06:46Z

0

Javascript does not allow passing function parameters by name

alert(isEmpty(Fname)); // instead of isEmpty(field=Fname)

answered May 14, 2013 at 10:06

shyam

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