Im designing a new site and I sought inspiration on the net. I went on www.download.com and liked what I saw. I then looked at the size for the main content and the width is 900 pixels. This would not fit in smaller browsers like 800*600.

On this website is the size dependant on the users computer screen?

Can you make adjustable sizes depending on the size of the screen?

Would be using a fixed 900 pixel size for main content that was aligned center be stupid?

Thanks in advanced.

Can you make adjustable sizes depending on the size of the screen?

Yes, if you use CSS and apply techniques that will scale or shrink to fit.

Would be using a fixed 900 pixel size for main content that was aligned center be stupid?

Not stupid, but may not be wise. Regrettably there are still people using screen resolutions below 1024x768. One day we'll see 1024x768 be the minimum but it's not there yet. Anyone on 800 x 600 will have to scroll right and that is not considered acceptable for design.

and some folks have their screen set at 1024x768 but still have their browser narrower

Your choice in design width might also have something to do with your visitors. If your site is high tech in nature it's probably more likely that your visitors will have higher resolution monitors though like blue-dreamer said they may not all have their browser maximized.

One thing you can do is develop your site with a liquid layout where some of the elements will expand and contract with the reolution. My current site is coded this way. I developed it so it looks it's best (I hope) between 1024x768 and 1600x1200, but the main content are will resize itself so you should still be able to view the site down to 800x600 without having to scroll horizontally and the site will expand to fill the screen at higher resolutions.

Typically liquid layouts will still have a column or two of fixed widthm but have at least one column that expands and contract so the overall site will expand and contract. It will take a little longer to code and it's a little more difficult to develop, but not overly so.

Otherwise I'd still go with a width that fits at 800x600 unless you know your visitors all have higher resolution monitors.

How about a computert help and advice site then?

Like I said above if you're up for it I'd try a liquid design. If you want to go for a fixed width design I'd still use 800px for now since enough people still have 800x600 browsers. The only way to know for certain the resolution of your site's visiitors is to look at your site statistics.

For my site I still get anywhere from 4%-8% visits from people with 800x600 resolution which for me is enough to want those people to see the site without scrolling.

I normally use 755 px wide to allow it to fit perfectly. However, it looks too small in the bigger window sizes.

my $.02

The smaller width can look cramped in higher resolution monitors and when I say I design for 800px I don't literally use 800px. More like 750px or 760px.

I think the liqid approach is the better one though you can still design a fixed width site that doesn't seem as small. You can leave the design open for example so the main area doesn't have a border around it which might give the appearance of the whole area extending farther than it does.

I use fluid (liquid) designs to for my websites, but normally have a logo/header with around 790 so if they make their browser smaller than 790 they will have to scroll right. But anything over that will expand itself to their screen size. I think this is the best option

Mark