Cant move focus to the control because its invisible , not enabled, or a type that does not accept the focus.

In that case don’t waste time trying to understand it, odds are you have conflicting ids in your document. Also, remember IE 7 and the previous versions are alone to think a name attribute should be treated like an id.

If that’s not it, then it’s because your html object is not considered active and visible on the page. It could be because the innerHTML is not done inserting, because the browser has not refreshed the DOM or because Orion is in Sagittarius’ house, but you have to find a way to slow your code’s execution.

But that’s always the programmer’s fault, of course. It turns out Javascript isn’t made to be used in a object-oriented way, but rather in a prototype-oriented fashion.

This lengthy post compares Java and Javascript and explains how a Javascript programmer should implement object inheritance.

I found a few things strikingly useful in there, notably the delegation of the whole obj.prototype reference and the fact he never explicitly declares any class attributes as he does in Java (and how I was trained to do it).

Yahoo! is not a place I like to hang around. I guess it has all to do with how they handled the presentation of their search results back in the day. I never was a fan of categorized results — at least wasn’t ready to try harder to use them at that time.

So, for years I’ve been using AltaVista and then Google instead of Yahoo! search; Hotmail, then GMail instead of Yahoo! mail. Since I don’t like to be overrun with data, I don’t even read the news on their portal. The NY Times‘ and Radio-Canada’s RSS feeds suit me better.

In other words, I am not part of the gazillions of people that help make Yahoo! the most important website on the Internet at the moment, according to Alexa. I didn’t have much of an opinion on Yahoo! until they got so useful for the web developer I am.

YUI

Yahoo! Developer Network is a priceless resource for information on popular web technologies. What I’m more interested in however is the YUI section — the Yahoo! User Interface Libary.

Javascript

YUI is said to be built around Yahoo!’s own Javascript library. Similar to jQuery and Prototype, the YUI library helps writing Javascript code that is more efficient more quickly. At the time of this writing, Yahoo!’s library has proven to work faster than its competitors when working on the DOM. A massive advantage on its competitors is its structured verbose that seems closer to more classic programming languages.

Notably, you can create namespaces for your scripts as well fire as custom events. Obviously, you can create visual effects of custom controls for your interface using objects the community is developing. Broken down in many files, you can import only the libraries you need in your application from Yahoo!’s servers. No hassle in storing multiple version of the files.

Templates

The section supplies a collection of pre designed templates for anyone to use. Whether you need a 3 column fixed layout, or fluid 100% wide 5 columns templates, you will find the XHTML and CSS files in the YUI section completely free. Free as in no charge, but also free as in open source.

Cross-platform

Most importantly, the library is guaranteed to be working the same on any Grade A browser. Other libraries don’t always live up to that mention as the script gets more complicated. This guideline is to be followed religiously, no matter if you are using Yahoo! products or not. The chart provides great arguments when you need to justify your decision to you employer when asked to design for IE3.

Standard Pipes

While the tools themselves are incredibly useful and time saving, it’s not the best thing about the YUI. Through guidelines, tutorials and free files, Yahoo! is lowering the pain of doing web design for people who don’t know about standards, don’t want to dig in or who just don’t care. If an important company like Yahoo! continues providing resources and using their influence in the developer’s community and the software makers building the browser, the Internet can standardize fairly quickly.

Yahoo! seems to be pushing towards a better Internet and the same cannot be said of everyone in the top-most influential websites.