Oracle Forms

Hi ,
I have one transaction table which is having some detail record under one transaction number, after the one transaction number is over by insert or update, i
want to check the total amounts of one flag should be matched on same table if it is not then give error message. But i am getting mutating error on insert or update event trigger on statement level trigger on above table.
Is there any other way to avoid mutating error to solve the above problem or some temp table concepts to be used. help me its urgent.

Thanks in advance,

Sachin Khaladkar
Pune