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javascript variable issue

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Join Date: Jun 2005

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michael123 michael123 is offline

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javascript variable issue

Mar 6th, 2008

I have a form text field called "field_0", and javascript code:

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<script language="javascript">
function test() {
var a=document.form1.field_0.value;
alert (a);
}
</script>
<form name=form1 ....>
<input type=text name=field_0>
<input type=text name=field_1>
<....onclick='javascript: test();'>
</form>

if I run this, it pops up correct message box with the "field_0" value.

However if I change a little in javascript code:

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<script language="javascript">
function test() {
var fd="field_0";
var a=document.form1.fd.value;
alert (a);
}
</script>

this script will no longer work, how can I use variable "fd" in "document.form...."? any idea?

Thanks.

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Join Date: Jan 2008

Posts: 483

Reputation: DangerDev has a spectacular aura about

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DangerDev

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Re: javascript variable issue

Mar 7th, 2008

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var fd="field_0";

here fd is a variable having value "field_0"

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var a=document.form1.field_0.value;

here field_0 is an object inside form1.

so you cant do what you want to do ?
any way why actually you want this to be done ?
you can try alternatives like getElementById();
hope this helps !!!

Freedom in the Mind, Faith in the words.. Pride in our Souls...
Indian Developer
http://falaque.wordpress.com/

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Join Date: Jun 2005

Posts: 92

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michael123 michael123 is offline

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Re: javascript variable issue

Mar 7th, 2008

thanks, that help me.

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Join Date: Jun 2005

Posts: 92

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michael123 michael123 is offline

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Re: javascript variable issue

Mar 7th, 2008

Another issue:
getElementById() works only in IE, if I try to use Firefox this will not work, how to solve this issue?

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Join Date: Jun 2006

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~s.o.s~

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Failure as a human

Re: javascript variable issue

Mar 7th, 2008

> I have a form text field called "field_0", and javascript code:

First of all, your markup is broken. The HTML tag attributes need to be in the form of key-value pairs with the value being enclosed in double quotes.

> However if I change a little in javascript code this script will no longer work

This is because your JS code now looks for an element with the name 'fd' instead of 'field_0'. Try something like document.form1[fd].value .

But the way you are accessing forms is fundamentally broken, read this excellent article on form access.

The romantic image of an über-programmer is someone who fires up Emacs, types like a machine gun, and delivers a flawless final product from scratch. A more accurate image would be someone who stares quietly into space for a few minutes and then says “Hmm. I think I’ve seen something like this before.” - John D