help with triggers

Hi,

[Quoted] I have a problem with on triggers:

is it possible to update one row in a trigger if a change of the same was the triggering event??????

here is my trigger and the (useful??) Oracle error messages :

   1 create trigger penalty_4
  2 after update of Real_Branch_in on contract   3 for each row
  4 begin

  5     if (:new.real_branch_in<>:old.pred_branch_in) then
  6     update contract
  7     set total = total +50 ;
  8     end if;

Trigger created.

SQL> _at_test;
update contract

       *
ERROR at line 1:
ORA-04091: table OPS$CS95LP.CONTRACT is mutating, trigger/function may not see
it
ORA-06512: at "OPS$CS95LP.PENALTY_4", line 3 ORA-04088: error during execution of trigger 'OPS$CS95LP.PENALTY_4'

Thanks for any help ......  

-- 
Laurent PHELEP                                      		 /\
Third Year Student in Computer Science                		 \/
University of Exeter                                  	       <>  <>
Email : L.Phelep_at_ex.ac.uk     				         /\
http://www.dcs.exeter.ac.uk/ug/cs95/lp/             		/  \
                                                   	       /    \
Kenavo                                           	      / /\/\ \