$sql = "insert into table values('".$value1."', '".$value2."'), ('".$value3."', '".$value4."')";
mysql_query($sql);
or
$sql = "insert into table values('".$value1."', '".$value2."')";
mysql_query($sql);
$sql = "insert into table values('".$value3."', '".$value4."')";
mysql_query($sql);