Forms :: Populating Form With Calculated Values

I have a form in which the fields are calculated fields. So i need to populate the form after calculating the values based on a database columns. For example if i have a table as below

COL A | Col B | Col C | Col D
2 3 4 5
3 4 5 6

I have 3 fields on my form which i need to populate such that field1 maps to col A. Field2 value is COL B * COL D for that value of COL A. Field 3 value is COLB * COL D for that value of col A.

I tried something like this

PROCEDURE NAME IS

cursor c1 is SELECT * FROM TABLEL;
begin
go_block('Block1');
clear_block(no_validate);
for i in c1 loop
:BLOCK.field1 := i.COL_A;
[code].......

this fetched all the records for field1 but for field2 and field3 it only calculates and populates the field row.