Create dynamic variable names

Hello all,

For a local invoice program I am writing, I want to calculate the
subtotal per line. Whenever a value is changed on that line the function
calculate_subtotal is called. On this line I have three variables:
product_aantal_ *line number*
product_prijs_ *line number*
product_totaal_ *line number*

*line number* can be any number between 0 and 9. It depends on the line
being changed.

The below code works fine in Opera and in IE but not in Firefox. I
managed to get it working in FF by using eval() but then it no longer
works in Opera or IE.

I have tracked it down to the problem being
getElementById('product_aantal_'+regel). It doesn't like the +line to
create the variable name.

Is there a uniform solution to this or is FF just not Javascript enough
compliant?

Thanks a lot,

RolandD

begin code:
----------------------
function calculate_subtotal(line) {
var regel = line.name.charAt(line.name.length - 1);
var aantal_waarde =
document.getElementById('product_aantal_'+regel).v alue;
var prijs_waarde = document.getElementById('product_prijs_'+regel).va lue;
var product_waarde =
document.getElementById('product_totaal_'+regel).v alue;
subtotaal = aantal_waarde*prijs_waarde;
subtotaal = formatAsMoney(subtotaal);
document.getElementById('product_totaal_'+regel).v alue = subtotaal;
}
----------------------
end code

"RolandD" <rdalmulderno (AT) spamhotmail (DOT) com> kirjoitti
viestissä:42e264bb$0$12749$ba620dc5 (AT) text (DOT) nova.planet.nl...

Hello all,

For a local invoice program I am writing, I want to calculate the subtotal
per line. Whenever a value is changed on that line the function
calculate_subtotal is called. On this line I have three variables:
product_aantal_ *line number*
product_prijs_ *line number*
product_totaal_ *line number*

*line number* can be any number between 0 and 9. It depends on the line
being changed.

The below code works fine in Opera and in IE but not in Firefox. I managed
to get it working in FF by using eval() but then it no longer works in
Opera or IE.

I have tracked it down to the problem being
getElementById('product_aantal_'+regel). It doesn't like the +line to
create the variable name.

Is there a uniform solution to this or is FF just not Javascript enough
compliant?

This is just a guess, but it's the most common mistake people make. Let me
guess, in your page you have inputs that you call with getElementById()? And
the elemenets have names.
<input name="product_aantal_7" type="...>

Do they have id's? So that you can call an element by it's id, it must have
one. And the most common problem is that internet explorer treats names as
id's. Unless you have

<input name="product_aantal_7" id="product_aantal_7" type="...>

in your form, getElementById(...) will work in IE, but _not_ in Firefox. IE
is the one to blame, Fx works correcttly as it ignores the name attribute if
no ID is provided. name is not the same as id. Make sure you are using id's
in your form elements.

--
"I am pro death penalty. That way people learn
their lesson for the next time." -- Britney Spears

eternal.erectionN0 (AT) 5P4Mgmail (DOT) com

Hello Kimmo,

Thanks a lot, that was the issue. Spot on. Thanks a million. A real noob
issue if you ask me

Regards,

Roland