delete a data from 3 tables

[Chandra N]

hi all
 
I created 3 tables namely authen_tbl,profile_tbl,astro_tbl,in which column
name mail  as primary key in authen_tbl table ,
query:
 pid int primary key auto_increment,
 foreign key (mail) references authen_tbl(mail) 
given in astro_tbl table 
and 
query
foreign key(pid) references profile_tbl(pid) 
given in astro_tbl.
 
My problem is how to delete a data at a strech from 3 tables.
 
Thanks 
chandra