This will work if you don't want it to save the selection over different sessions.
PHP Code:
if (!$css) $css="default";
switch($css){
// Set default css file if none is selected in the URL.
case "default":
$css = default.css;
break;
//Modify below for each css choice.
case "css1":
if (@join ('', file ("customer1.css"))=="")
$css = default.css;
else
$css = customer1.css
break;
// Don't modify below except to set your default css file.
default:
include("default.css");
break; }
Then for the HTML part, if it's
not within PHP tags, simple use
PHP Code:
<link href="<? echo $css;?>" rel="stylesheet" type="text/css">
Else, if it is...
PHP Code:
echo "<link href='$css' rel=\"stylesheet\" type=\"text/css\">"