Home/ Questions/Q 439161
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-12T20:44:56+00:00

I have the following layout with a sidebar that is only present on some

  • 0

I have the following layout with a sidebar that is only present on some pages and not others. When the sidebar is not present #main should fill the available width of the container.

It works but makes use of a CSS expression – is it possible to achieve the same layout without this expression?

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="content-type" content="application/xhtml+xml; charset=utf-8" />
<style type="text/css">
/* reset css */

* {
    border: 0px none;
    margin: 0;
    padding: 0;
    vertical-align: baseline;
    font-family: inherit;
    font-style: inherit;
    font-weight: inherit;
    font-size: 100%;
}

/* end reset */

#container {
    margin: 0 auto;
    width: 800px;
    background-color: red;
}

#sidebar {
    display: inline;
    float: left;
    width: 130px;
    background-color: green;
}

#main {
    float: left;
    background-color: blue;
    width: expression(document.getElementById('sidebar') == null ? "100%" : "670px");
    max-width: 100%;
}

#sidebar + #main {
    width: 670px;
    background-color: yellow;
}

#clear {
    clear: both;
    height: 1px;
    font-size: 0px;
}
</style>
</head>
<body>
<div id="container">
    <div id="sidebar"><p>This is the side bar</p></div>
    <div id="main"><p>This needs to expand to fill available width, what if I have sufficient content in here to push this div so it spans across the whole width of the page like so...</p></div>
    <div id="clear"></div>
</div>
</body>
</html>
Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    The + adjacency selector would do it, except in IE6 where it isn’t supported. The usual workaround would be to add some extra class information:

    <div id="container" class="with-sidebar">

    and then select on that in the stylesheet:

    #sidebar { float: left; width: 130px; }
.with-sidebar #main { margin-left: 130px; }

    This needs to expand to fill available width

    Then don’t bother make it float; I’m not sure what that’s supposed to achieve.

    Also avoid ‘inherit’ rules, they don’t work in IE previous to version 8.

    • 0