Código PHP:
<?php
$link=mysql_connect("localhost","user","pass");
mysql_select_db("db", $link);
$clave = $_GET['clave'];
if ($clave<>''){
{
$trozos=explode(" ",$clave);
$numero=count($trozos);
if ($numero==1)
{
$cadbusca="SELECT * FROM tabla WHERE NOMB LIKE '%$clave%' OR AUTOR LIKE '%$clave%' OR TEMA LIKE '%$clave%'OR EDITORIAL LIKE '%$clave%' OR OBSERVA LIKE '%$clave%'order by AUTOR limit 50";
}
elseif ($numero>1)
{
$cadbusca="SELECT * , MATCH(NOMB, AUTOR) AGAINST ('+$clave') as Score FROM vells
WHERE MATCH (NOMB, AUTOR) AGAINST ('+$clave') ORDER BY AUTOR";
}
$result= @mysql_query($cadbusca,$link);
while ($row=@mysql_fetch_array($result))
{
echo $row['AUTOR'] ;echo $row['NOMB'];echo $row['PVP']; echo "<br>";
// echo $row['NOMB'];
}
}
}else if (isset($clave)) {
$cadbusca="SELECT * FROM tabla WHERE NOMB LIKE '%$NOMB%' OR AUTOR LIKE '%$AUTOR%' order by AUTOR limit 50";
}
?> 
