Forms :: Passing Check Box Values To WHERE Clause?

I have created a Data block - 'CONTACTS' (Database data block) and has database item - 'Code', 'Descr'

The number of records displayed is set to 5.

Value When checked - 'Y'
Value When Unchecked - 'N'
Check box mapping of other values - 'unchecked'

The requirement is when i check one or multiple checkboxes, i should pass the 'Code' item values to the WHERE clause.

Right now whenver i am trying to do so, only the current record value is copied to the WHERE clause.

I have tried using basic loop as well as while loop but things havmt worked. Below is a basic code which will work for one record, request to guide me with muliple checkbox ticked.

IF :contacts.cb = 'Y' THEN

IF p_where is null then

p_where := :contacts.code;
else
p_where := p_where ||','||:contacts.code;
end if;
end if;
p_where:= 'where code in ('||p_where||')';