第一个：
if($http_host==www.moon-soft.com){
header(location: moon.htm);
}
elseif($http_host==www.williamlong.info){
header(location: williamlong.htm);
}
else{
header(location: other.htm);
}
第二个：
if($http_host==www.moon-soft.com){
require moon.htm;
}
elseif($http_host==www.williamlong.info){
require williamlong.htm;
}
else{
require other.htm;
}