well, you sure as hell should keep in mind that some people have javascript disabled, which isn't as stupid as some might think.
so if your site depends on javascript, it sucks hehe.
i use javascript for my login system (i calculate in md5 hash of my password before i post my form. like that, someone sniffing the network won't be able to get my password...), but only because i'm the only one who is supposed to log in anyway and i have javascript enabled, so that's no problem.
dhtml.. nonono!

well i think that js has some good side and also a professional side like a client form validation before server side validation, it helps for some instances. and much more, i thought it's useless and evil but it's quite interesting

It has good ways of implementation and good concepts are possible with it, but the language itself is just a screwup. They should make a new client side language like it, and do it right this time.

hmz, what's so bad about javascript,, the languague?

• First of all, incompatibilities. Few browsers support the large gamma of functions JavaScript offers. And you have specific browsers that decided to make specific JavaScript functionalities which only work on their browsers, like Microsoft IE & Netscape. Thus, people working with those browsers, and using them as only testing browser will generate JavaScript which is fucked in other browsers, completely screwing the primairy objective of a Web Application / Site, which is compatibility. They argue that IE is used by many people. This arguement only proves how lame and shortminded they are.
• Secondly, JavaScript parsers are a pain in the backside, especially the Internet Explorer one. Code goes wrong when there is no reason for it to go wrong, because, for example, a div in the body didn't load in time, and the script can't find it.
• Many browsers don't even have JavaScript parsers, which causes them to be unable to browse a specific site that depends on it.
• JavaScript is insecure. It allows far too much datagathering, and allows for people to abuse holes in software. Holes are unpreventable, but JavaScript is a gate to take hackers there. Any clientsided script is a victim of this, unless if there are extensive restrictions. Java does a very good job, they should learn from it.
• Most of all, the users which incorperate it. They are stupid and retarded. They don't realise that their code is evil, and they can't be bothered to learn JavaScript decently. Browsers should give parsing errors and not display the website should there be problems with the code, just like a Java compiler won't allow a program with screwed syntax to be run.

sure, i knew all that. but why make another language. javascript itself is pretty good. it's the browsers and the users that make it sucky.

you could compare it to dynamite, which was invented to do good, and does the job very well, but people use it for the wrong purposes.

most incompatibilities are because of the dom structure anyway, not because of javascript

Well, there should be a standardised language designed and documented in such a way that it can almost not be extended further, that it provides in all basic needs, so that it needn't be extended further. The DOM structure should be rebuilt as well, true, learning from the mistakes that were revealed with this. But most importantly, two major things :
Faulty webpages shouldn't render. At all.
Browsers should stick to the standards.

If you create a language that provides in most basic DOM access needs, and all browsers use those standards, (even should they extend it further), then users using those standards alone will have webpages that Work. Nowadays, things aren't as easy as that.
And those two statements I stated, are universal. Not just concearning clientside scripting, but also concearning CSS, HTML, SGML, etc.. If only W3C had the authority to penalise all browsers that didn't support the standards correctly.

you've forgot to mention about ECMAScript
it is the standard javascript version

Plain HTML result is general no problem to most users but a little Javascript to add info like guide on a topic (click and expand will explaination, click again to hide it) will help to help users with slow connections (no need to reload the whole page again).

Like all other programs, if it is use wisely, it will be handy.

Please bear in mind to use only small and basic/simple method scripts.
Don't use more than 2 or 3 types of Javascript function in one page.

Please comment, thanks people!

That's where things go wrong, avalon, because alot of those kinds of scripts work in IE, for example, but fail in Opera or Mozilla / Firefox / ...
This is where you should be using CSS rather than JavaScript anyway. CSS alows for far more dynamic adjustments. Keeps things clean & easy & simple, whereas, if you look a JavaScript code..... it's all but clean, easy or simple. Not compared to CSS anyway.
IE does have alot of difficulities with CSS, but I'd rather use a compliancy patch for IE (IE7) to fix IE, rather than JavaScript scripts to do that.