Help with a query please

Hi, I have the following table structure, as my installation of MySQL doesnt support Foreign keys i have to maintain the referential integrity myself. So if i delete a user, how can i make sure that the allocations from the allocations table where the user_id is the same as the one being deleted and that bookings are deleted where the allocations_id is the same as the allocations deleted for that user_id? Thanks for your help # ---------- MySQL dump ---------- # # Table structure for table 'WMS_Allocations' # CREATE TABLE WMS_Allocations ( Allocation_ID int(11) DEFAULT '' NOT NULL auto_increment, Project_ID int(11) DEFAULT '0' NOT NULL , User_ID int(11) DEFAULT '0' NOT NULL , PRIMARY KEY (Allocation_ID), KEY Project_ID (Project_ID,User_ID) ); # # Table structure for table 'WMS_Bookings' # CREATE TABLE WMS_Bookings ( Booking_ID int(11) DEFAULT '' NOT NULL auto_increment, Booking_Date date DEFAULT '0000-00-00' NOT NULL , PCT_address varchar(255) , PCT_postcode varchar(255) , PCT_telephone varchar(255) , PCT_manager varchar(255) , PCT_gp varchar(255) , P_address varchar(255) , P_postcode varchar(255) , P_telephone varchar(255) , P_manager varchar(255) , P_gp varchar(255) , Allocation_ID int(11) , PRIMARY KEY (Booking_ID), KEY Allocation_ID (Allocation_ID) ); # # Table structure for table 'WMS_Projects' # CREATE TABLE WMS_Projects ( Project_ID int(11) DEFAULT '' NOT NULL auto_increment, Project_Name varchar(255) , PRIMARY KEY (Project_ID) ); # # Table structure for table 'WMS_User' # CREATE TABLE WMS_User ( User_ID int(11) DEFAULT '' NOT NULL auto_increment, User_Username varchar(100) DEFAULT '' NOT NULL , User_Password varchar(100) DEFAULT '' NOT NULL , User_Name varchar(100) DEFAULT '' NOT NULL , User_Type int(11) DEFAULT '0' NOT NULL , User_Email varchar(100) , PRIMARY KEY (User_ID), UNIQUE User_Username (User_Username) );