Question: Given the code below:

```js
function test() {
    document.forms[0].TEST[0].focus();
}
```

```html
<form>
    <input type="button" value="Test" onclick="test()" />
    <input type="radio" name="TEST" value="A">A
    <input type="radio" name="TEST" value="B">B
</form>
```

In IE6, clicking the button doesn't focus the control, unless I've already tabbed through the radio at least once, in which case it works. =/

Any idea how I should be focusing the control? The above works perfectly fine in FF of course.

Edit: I found that the control is being focused, except the highlight box around the radio button is not being rendered. (I can hit space to activate the radio button, and also use arrow keys to change the active button). So the question becomes: how can I force the focus highlighting box to render?

Answer: 
My general rules of thumb are as follows

* If it needs to always run, it's a service.
* If it needs to be run under a particular user account, Network Service, Local System, generally it's a service (or a COM+ application)
* If the user needs some control over it, it's generally a notification area application.
* If it needs to notify the user of something, it's a notification area application

The fun comes when you have the need to run something as a system account, but also interact with it. IIS is a good example of this, it's a service, but the administration is an application - it needs to be running at the startup, it needs access to particular things a user can't normal access (c:\inetpub), but the user needs to be able to start, stop and configure it.
I believe your decision is almost right, however, I would add one more condition. Take for example the mysqld service (you have a choice in this case, but most people run it as a service). It's ran as a service because you want to access the service anytime through potentially multiple applications. It's important that it is responsive to all applications calling upon it, and itself, is not much of anything, other than waiting to serve other applications.

Just something I would consider as well when making my decision.