create table help

[Ruth]

I'm using sql 5.1 running on unix. I have four tables I'm trying to link together through one table. I have a client, agency, phone log and employers table already built. When I try to create my placement table (link table) I get the following error:

 

ERROR 1005 (HY000): Can't create table './netpro/placement.frm' (errno: 150)

 

Here is my create table statement:

 

create table placement (

pclient_id int,

pagent_id char(20),

plog int,

pemp_id int,

start_date date,

pay int,

constraint pk_placement

primary key (pclient_id, pagent_id, plog, pemp_id),

constraint fk_pclient

foreign key (pclient_id) references client

on update cascade

on delete cascade,

constraint fk_pagent

foreign key (pagent_id) references agency

on update cascade

on delete cascade,

constraint fk_plog

foreign key (plog) references phone_log

on update cascade

on delete cascade,

constraint fk_pempid

foreign key (pemp_id) references employers

on update cascade

on delete cascade

) engine = innodb;

can anyone help me