Insert statement always makes value as 0

[trickee]

Can anyone see why maybe this set of select/insert statements always inserts a value 
of 0 instead of the selected site id in the first select statement? The variable 
$getid should hold the site id to be entered into the table ssx but its always entered 
at 0 and I get no php or mysql errors. Any help would be appreciated, thanks.

$selectid="SELECT site_id FROM sites WHERE domain = \"$domain\"";

$getid = mysql_query($selectid);

echo mysql_error();
  
$hostsql2="INSERT INTO hostnames ( sid, hostname, ethernet_ip )  VALUES ( 'NULL', 
'$hostname', INET_NTOA('$ethernet_ip'))";
  $hostresult2=mysql_query($hostsql2);

echo mysql_error();
  
$details2="INSERT INTO details ( sid, os, home_dir, date, processor, memory, installs 
) VALUES ( LAST_INSERT_ID(), '$os', '$home_dir', '$date', '$processor', '$memory', 
'$installs')";
  $detailsresult2 = mysql_query($details2);
  
$ssx2="INSERT INTO ssx ( id, sid, site_id ) VALUES ( 'NULL', LAST_INSERT_ID(), 
'$getid')";
  $ssxresult2 = mysql_query($ssx2);