Forms :: Populate_list For Non Database Field

in my forms,1 block(multi record)) which has 5 database columns(c1,c2,c3,c4,c5) and 1 non-database column(s1).Forms shows column c4 ans s1. I use populate_list on s1 column on basis of value c1,c2,c3 using system.mouse_record to fetch respective record values in the list.

but getting problem of list pop up size and return value on selecting value from pop up list. means clicking on 1st record and selecting value(e.g val1),its return "val1" after that clicking on 2nd record and selecting value(e.g xyz),its return "xyz" but at that time 1st record value become "xyz" instead of "val1".mns its replace all values with current selected value from the list.

Original code for reference as below.

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PROCEDURE S_VALUE_LIST IS
rg_id RecordGroup;
lst_id Item := Find_Item('SNSPECMST.S_VALUE');
ERRORCD NUMBER;
t_srno1 number := 0;
t_srno2 number := 0;
t_srno3 number := 0;
BEGIN
[code]...