Retrieving form values in Javascript

[namanhvu]

Hi everyone,

I am trying to create a form for authorised users to upload photos to
an image gallery. I'm attempting to perform simple validation of the
fields by ensuring the fields aren't empty and that the extensions are
right. However, I can't seem to access the actual values of the fields
to start with.

If I simplify my problem, can anyone tell me why this would work in a
Javascript alert:

alert(document. form.Photo1.val ue);
//This outputs 'D:/images/x.jpg'

but this won't:

var photonumber = "Photo" + 1;
alert(document. form.photonumbe r.value);
// I get "undefined"

The reason I'm doing this is because I'm looping through a finite set
of images and need to check each one is valid.

Is it because I'm not initialising the "photonumbe r" string correctly?

If there are any geniuses out there, please help this newbie.

Thanks in advance!

Nat.

[web.dev]

naman...@gmail. com wrote:

Hi everyone,

I am trying to create a form for authorised users to upload photos to
an image gallery. I'm attempting to perform simple validation of the
fields by ensuring the fields aren't empty and that the extensions are
right. However, I can't seem to access the actual values of the fields
to start with.

If I simplify my problem, can anyone tell me why this would work in a
Javascript alert:

alert(document. form.Photo1.val ue);
//This outputs 'D:/images/x.jpg'

but this won't:

var photonumber = "Photo" + 1;
alert(document. form.photonumbe r.value);
// I get "undefined"

>From your description it sounds like the most likely place it is

causing an error is in Internet Explorer. That is because you are
using a variable name that is the same as the form name. Try a
different variable name.

[Randy Webb]

web.dev said the following on 9/28/2006 9:11 PM:

naman...@gmail. com wrote:

<snip>

>but this won't:

var photonumber = "Photo" + 1;
alert(document .form.photonumb er.value);
// I get "undefined"

>>From your description it sounds like the most likely place it is

causing an error is in Internet Explorer. That is because you are
using a variable name that is the same as the form name. Try a
different variable name.

No, it is because there is no form element named "photonumbe r", and it
won't replace the variable with it's value in dot notation. What will
work however is something like this:

document.forms['form'].elements[photonumber].value

--
Randy
Chance Favors The Prepared Mind
comp.lang.javas cript FAQ - http://jibbering.com/faq & newsgroup weekly
Javascript Best Practices - http://www.JavascriptToolbox.com/bestpractices/

[Dr John Stockton]

JRS: In article <11************ **********@b28g 2000cwb.googleg roups.com>,
dated Thu, 28 Sep 2006 17:18:30 remote, seen in
news:comp.lang. javascript, na******@gmail. com posted :

>var photonumber = "Photo" + 1;
alert(document .form.photonumb er.value);
// I get "undefined"

>If there are any geniuses out there, please help this newbie.

One only needs the ability to read the newsgroup FAQ, 2.3, 4.41 & 4.39;
see below.

--
© John Stockton, Surrey, UK. ?@merlyn.demon. co.uk Turnpike v4.00 IE 4 ©
<URL:http://www.jibbering.c om/faq/>? JL/RC: FAQ of news:comp.lang. javascript
<URL:http://www.merlyn.demo n.co.uk/js-index.htmjscr maths, dates, sources.
<URL:http://www.merlyn.demo n.co.uk/TP/BP/Delphi/jscr/&c, FAQ items, links.

[namanhvu]

Thanks to everyone who replied.

I got it to work by doing the following:

alert(document. form.elements[name].value);

Nat.
Dr John Stockton wrote:

JRS: In article <11************ **********@b28g 2000cwb.googleg roups.com>,
dated Thu, 28 Sep 2006 17:18:30 remote, seen in
news:comp.lang. javascript, na******@gmail. com posted :

var photonumber = "Photo" + 1;
alert(document. form.photonumbe r.value);
// I get "undefined"

If there are any geniuses out there, please help this newbie.

One only needs the ability to read the newsgroup FAQ, 2.3, 4.41 & 4.39;
see below.

--
© John Stockton, Surrey, UK. ?@merlyn.demon. co.uk Turnpike v4.00 IE 4 ©
<URL:http://www.jibbering.c om/faq/>? JL/RC: FAQ of news:comp.lang. javascript
<URL:http://www.merlyn.demo n.co.uk/js-index.htmjscr maths, dates, sources.
<URL:http://www.merlyn.demo n.co.uk/TP/BP/Delphi/jscr/&c, FAQ items, links.