Would you mind posting a screen shot of what it is you are referring to?
There is no option in XOOPS to control the width of your site based on screen size. This is handled at the presentation layer, that being your theme.
Usually, the width of the theme (and it's various elements) are controlled in the theme's theme.html file, or more appropriately, in its stylesheet (style.css).
In either case, you'll want to look for code that defines width.
For instance, in theme.html, you would look for HTML attributes like so...
<table cellpadding="0" cellspacing="0" border="0" [b][color=FF0000]width="768"[/color][/b]>
You would want to change the above to the following...
<table cellpadding="0" cellspacing="0" border="0" [b][color=FF0000]width="100%"[/color][/b]>
It's quite a bit easier to change widths in CSS. However, you'll need to identify which element in your theme's HTML is being controlled by the CSS to set width.
For instance, in theme.html, you would look for HTML attributes like so...
<div [b][color=FF0000]id="wrapper"[/color][/b]>
In your style.css, you would want to look for
wrapper and change the value assigned to it. For example...
Change
wrapper {width: 768px;}
To
wrapper {width: 100%;}
The above is only an example, and depending on your theme, the elements and attributes may vary greatly. However, the above should give you an idea of what to look for.
As with all things, backup your theme before you start making changes. A change in one area often affects other elements in a theme, so some tinkering with your theme may be required to get it to do exactly what you want.
You will also need to empty the contents of the templates_c directory before your changes to your HTML will take effect.
If you're not familiar with HTML and CSS, may I suggest a handy little website...
http://w3schools.comHope this helps.
James
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