http://www.w3.org/TR/2003/REC-DOM-Level-2-...tml#ID-14493106
| Parameters
| element of type HTMLElement
| The element to add.
| before of type HTMLElement
| The element to insert before, or null for the tail of the list.


ciao, dhgm

Using "appendChild" instead of "add" will do the trick.

...
case "Amphipoda" :
document.getElementById("clas").appendChild(new
Option("Gammaridae","Gammaridae"));
break;
...

Also, ensure that the "clas" select element has an id="clas" as
well as a name="clas". IE treats them as synonymous, which is
incorrect.

In IE, getElementById('clas') will return a reference to a form
element with name='clas' even if it has no id - but not so in
Firefox.

For further info, 'name' and 'id' share the same namespace, so if
you want to use the same id and name, they must be on the same
element, but it is not compulsory for the name and id of a
particular element to be the same.

--
Rob.

In your example, use the 'add' method like this (works in IE and
Firefox):

case "Amphipoda" :

document.getElementById("clas").options.add(new
Option("Gammaridae","Gammaridae"));

break;


If you ant to add it at a certain position in the options
collection (say as the 3rd option) using clearer code:

var oOpt = new Option("Gammaridae","Gammaridae");
document.getElementById("clas").options.add(oOpt,2);

By not specifying a position, or using 'null', the option is
added to the end of the collection. So the appendChild method may
suit you better.



--
Fred

The language attribute is deprecated and redundant. Don't bother with it.

[snip]

If you're using the W3C DOM to manipulate the document tree, I
personally think it best to use it consistently; create the option
element with the createElement method, rather than the DOM 0 Option
constructor.

[snip]

The W3C DOM defines the HTMLSelectElement.add method as taking two
required arguments - both object references. The first argument you
know. The second specifies where to insert the new element in
precisely the same fashion as the Node.insertBefore method. However,
Microsoft (for whatever reason) do not implement the add method with
the same signature. The second argument is an optional number.

Obviously, these two approaches are incompatible. Whilst the Microsoft
model might be, in this case, better there is no reason why both the
proprietary and standard implementations couldn't be supported
simultaneously: Opera manages it.

A potential solution, though untested on Safari, Konqueror, and
earlier Mozilla version, is presented below:

function addOption(element, index, option) {var cN, o;
if('string' == typeof element) {
element = document.getElementById(element);
}
if('string' == typeof option) {
o = document.createElement('option');
o.text = option;
} else {o = option;}

if((cN = element.childNodes)) {
if(2 == element.add.length) {
element.add(
o,
((0 > index) || (cN.length == index)) ? null : cN[index]
);
} else {
element.add(o, index);
}
}
return o;
}

element - Either a reference to a SELECT element, or its id.
index - The position where the new element is to be inserted.
A value of -1 will append the new option.
option - This argument can either be a string representing the
text of the new option, or it can be a reference to
an OPTION element.

The function will return a reference to the new OPTION element. This
allows other properties, like value and selected, to be set once the
element has been added.

The function obviously needs some additional feature testing, and
perhaps a fallback for DOM 0 user agents. However, I think success
with browsers other than IE5.01+, Opera 7.54u1, and Firefox 1.0 needs
to be determined first.

I'm not quite sure what you mean there.

Mike

--
Michael Winter
Replace ".invalid" with ".uk" to reply by e-mail.

It seems to fail with IE. Whilst a new OPTION element is given space
on the control, no text appears. Oddly enough, the associated value
can still be submitted. It would seem that IE attaches some special
significance to the add method.

See my post for an (insufficiently tested) alternative.

[snip]

This is true for certain elements, such as FORM and IMG. However, it
is not for form controls (INPUT, SELECT, etc.). In the latter case,
the scope of name attributes is limited to the containing form
(assuming there is one).

This is true for form controls, but not other elements. Elements such
as A or FORM which have a name and an id attribute /must/ share the
same value.

Elements Scope Identical attributes

INPUT, SELECT, Form No
TEXTAREA, BUTTON

A, APPLET, FORM, Document Yes
FRAME, IFRAME,
IMG, MAP

Mike

--
Michael Winter
Replace ".invalid" with ".uk" to reply by e-mail.

Yes, I could have sworn I tested it in IE, guess I only did the
"add" version.

The vagaries of HTML - consistency? heaven forbid...

I think in future I'll just point to the relevant part of the
spec and be done with it :-p

--
Rob