META Tag ‘MSThemeCompatible’

Okay, so this one’s a little old, and I just found it while looking at some of Microsoft Update’s HTML source, it appears to be relevant for MSIE6 and newer and may be responsible for some interesting styling and behaviour of form components.

A quick search for it turns up lots of discussions about other browers such as Firefox being effected if the value is not defined… as such it’s likely a good idea to define it in your pages to be sure.

An old MSDN entry reads…

When running on Windows XP, Internet Explorer 6 and the content displayed in it sports a look and feel that matches the Windows XP platform. You can opt to have your HTML content not take on the same look as the operating system for elements such as buttons and scroll bars, by adding the following META tag:
<meta http-equiv="MSThemeCompatible" content="no" />

Setting this will disable theme support for the document. Some background on this, Windows XP (MSIE6) allows for the use of themes for the operating system to change the general color scheme of many elements.
As such, many HTML components (such as SELECT dropdowns, BUTTONS and INPUT fields ‘MAY’ also be effected if you don’t explicitly prevent it in your code.

There was some support for this in Mozilla Firefox builds for Windows, as such, while I’d normally recommend using a conditional comment, I’m torn in this case.


Adding Support for ‘disabled’ OPTION tags in MSIE

This is a very annoying bug/oversight in MSIE (including the recently released MSIE7!).

For some reason, Microsoft didn’t implement the ‘disabled’ attribute on <option> tags.
All other modern (even the old Netscape 4.x) browsers support this, why would they not do the same.
This is probably for the same reason that all versions of MSIE (prior to MSIE7) left the rendering of the SELECT tag to the operating system itself, above the browser HTML.
Thankfully, you can still access the attribute on the DOM element with javascript!

My solution has evolved over time, here’s the current release code.

To emulate this behavior in MSIE, you’ve got several different challenges to overcome.

  1. You must ‘persist’ the current value of the SELECT so that you can ‘restore’ it when the user chooses a disabled field, I do this during the onload event.
  2. When the ‘onchange’ event for the SELECT tag is invoked, the currently selected OPTION’s attributes must be read and checked.
  3. If the selected OPTION is ‘disabled’, then the previous value must be restored.
  • As this solution only stores one value per SELECT, the ‘multiple’ SELECT is not currently supported.
  • In the future I’ll probably do some ‘event injection’ so that the HTML itself is cleaner. Problem is that in more complex solutions like ‘dependent dropdowns’ this becomes tricky.
  • The [if IE] ‘comment’ is critical as it is conditional logic supported only in MSIE and simplifies what was previously done via various ‘browser-sniffing’ tricks.
  • The example code in this example excludes the CDATA escapes and several tags required for valid XHTML for brevity.
  • FYI, the example also contains the MSIE background-image cache fix discussed in a previous post.

<script type=”text/javascript”>
var isMSIE=false;
<!–[if IE]>
<script type=”text/javascript”>
<script src=”/js/grv-msie-hacks.js” type=”text/javascript”></script>

<script type=”text/javascript”>
function xload(){
function xchange(obj){
// note: javascript emulation of <option disabled…> (for MSIE)

<body onload=”xload();”>

<form action=”#” method=”GET”>
<select name=”s” id=”s” size=”1″ onchange=”xchange(this);”>
<option value=”n1″>Normal1</option>
<option value=”di” disabled=”disabled”>Dis</option>
<option value=”n1″>Normal2</option>

JavaScript file (grv-msie-hacks.js):

* Code library to add several ‘broken’ features in MSIE 6 and 7
* @version $Id: $
function grvMsieInitHacks(){
function grvMsieCacheFix(){
/* Added new functions to support <option disabled…> emulation
* First part, necessary for <body onLoad…>
* builds array of all initial selections for <select>s on page (for LT or EQ MSIE7)
* WAS: disabledOptionEmulation();
function grvMsieSelectFix_init() {
if (document.getElementsByTagName) {
var allSelects = document.getElementsByTagName(“select”); // build array of all <select> tags
if (allSelects.length > 0) { // if array has values…
window.allSelectsCurrentIndex = new Array(); // new array to hold initial selections
for (var i=0, individualSelect; individualSelect = allSelects[i]; i++) { // crawl through all <select> tags
individualSelect.onfocus = function(){ window.allSelectsCurrentIndex[] = this.selectedIndex; } // fill array with selectedIndex values

/* companion code for grvMsieSelectFix_init()
* resets <option> selection if disabled to last good selection (for LT or EQ MSIE7)
* WAS: restoreSelection(inOptionChoice)
function grvMsieSelectFix_restore(inOptionChoice) {
if (inOptionChoice.options[inOptionChoice.selectedIndex].disabled){
// if new choice is disabled…
inOptionChoice.selectedIndex = window.allSelectsCurrentIndex[]; // deny selection, revert back to last ‘known good’ choice (typically, the initial selection at page load)
} else { // if new choice isn’t disabled…
window.allSelectsCurrentIndex[] = inOptionChoice.selectedIndex; // update array so last ‘known good’ choice is now the latest user selection

Hopefully, Microsoft will get around to fixing this correctly some day… maybe for MSIE8!

<option disabled=”disabled”>?</option> not implemented in MSIE

This was a complete shock to me recently, even after years of ‘assuming’ that something this simple would be well supported… after all, this is pretty basic.

All modern browsers Mozilla (Firefox), Safari, Opera, even old Netscape (eg: 4.x) browsers work properly with the following code and comply with the W3C HTML specification making the value “Two” unable to be selected by the user within the browser… MSIE doesn’t comply and allows the user to select it!

<form name="example" action="#" method="get">
<select name="test">
<option value="1">One</option>
<option value="2" disabled="disabled">Two</option>
<option value="3" selected="selected">Three</option>
<option value="4" style="color:green;">Four</option>


This ‘failure’ to support standards actually seems to be due to the way the <select> tag is handled by the browser… it passes off control to the operating system (Windows). Obviously, Microsoft was able to pass along ‘other’ attributes, like ‘style’ in the example above, but chose to not support ‘disabled’.

In this case, the developer is left to find a solution… easiest is to just remove the unwanted value from the list of options, otherwise it requires extensive amounts of JavaScript.

Good luck!

NOTE: Tested on MSIE 6.0 (WinXP), hopefully Microsoft will fix this in MSIE7.