saya mau tanya nih mas gimana caranya meng-count tapi
bersumber dari bbrpa tabel jumlah sks,

bentuk tabel'y seperti ini

//tabel krs
CREATE TABLE `krs` (
  `id_krs` int(10) NOT NULL auto_increment,
  `NIMHS` varchar(10) NOT NULL,
  `KDSEMES` int(2) NOT NULL,
  `TAHUN` int(4) NOT NULL,
  `NMGANGEN` varchar(5) NOT NULL,
  `STATUS` varchar(10) NOT NULL,
  PRIMARY KEY  (`id_krs`)
//trans_krs
CREATE TABLE `trans_krs` (
  `id_trankrs` int(4) NOT NULL auto_increment,
  `id_krs` int(10) NOT NULL,
  `KDJADWAL` varchar(6) NOT NULL,
  `BU` varchar(1) NOT NULL,
  PRIMARY KEY  (`id_trankrs`)

//tabel jadwal1
CREATE TABLE `jadwal1` (
  `KDJADWAL` int(10) NOT NULL auto_increment,
  `HARI` varchar(10) NOT NULL,
  `JAM` varchar(12) NOT NULL,
  `KDMKM` varchar(10) NOT NULL,
  `NIDN` varchar(10) NOT NULL,
  `kdkelas` char(2) NOT NULL,
  `KDRUANG` varchar(5) NOT NULL,
  PRIMARY KEY  (`KDJADWAL`),
  KEY `KDMKM` (`KDMKM`),
  KEY `NIDN` (`NIDN`),
  KEY `KDRUANG` (`KDRUANG`)

//tabel makul
CREATE TABLE `makul` (
  `KDMKM` varchar(10) NOT NULL,
  `NAKMK` varchar(25) NOT NULL,
  `SKSMK` int(2) NOT NULL,
  `SKSTM` int(2) NOT NULL,
  `SKSPR` int(2) NOT NULL,
  `SKSLP` int(2) NOT NULL,
  `SEMES` varchar(1) NOT NULL,
  `KDWP` varchar(1) NOT NULL,
  `KDPS` int(2) NOT NULL,
  `KDKUR` varchar(3) NOT NULL,
  `KDPRODI` varchar(4) NOT NULL,
  `KDJEN` varchar(1) NOT NULL,
  `KDPT` varchar(7) NOT NULL,
  PRIMARY KEY  (`KDMKM`)

dan ini php'y

$result = mysql_query("select count(makul.SKSMK) as total from krs,trans_krs,jadwal1,makul where krs.NIMHS='$_SESSION[NIDN]' and krs.KDSEMES='$semester' and krs.TAHUN='$tahun'");

mohon pembenarannya krna saya bingung dg tabel penghubungnya dari bbrapa tabel.

$tampil = mysql_query("select * from mhs inner join krs on mhs.NIMHS=krs.NIMHS inner join trans_krs on krs.id_krs=trans_krs.id_krs inner join jadwal1 on jadwal1.KDJADWAL=trans_krs.KDJADWAL inner join makul on makul.KDMKM=jadwal1.KDMKM where mhs.NIDN = '".$_SESSION['NIDN']."' group by krs.KDSEMES ");
$jum = 0;
$r=mysql_fetch_array($tampil;
$jum = $jum + $r['SKSMK'];
echo "<td align='center'>".$jum."&nbsp;sks</td>";