summing the value of few fields

Hi,

I have a table whose declaration is like this:

TYPES : BEGIN OF ty_employeedata,

basic_salary TYPE ztable-basic_salary,

da TYPE ztable-da,

hra TYPE ztable-hra,

medical TYPE ztable-medical,

bonus TYPE ztable-bonus,

pf TYPE ztable-pf,

tax TYPE ztable-tax,

total TYPE ztable-tax,

END OF ty_employeedata.

DATA : it_employeedata TYPE TABLE OF ty_employeedata WITH HEADER LINE.

Now I am addidng the salary fields to get the salary:

it_employeedata-total = it_employeedata-basic_salary + it_employeedata-da +

it_employeedata-hra + it_employeedata-medical +

it_employeedata-bonus - it_employeedata-pf - it_employeedata-tax.

On debugging it is showing me the total but on screen it is not showing the value.Please suggest the solution.