Forms :: Update / Insert Records From One User To Other

I want to update / insert records from one user to other user therefore I write this code in my form but it gives me error.

REPORT_DETAILS is a detail table of REPORT_PARAM, given code is working fine at master tables.

Form always goes in TOO_MANY_ROWS exception.

Correct my code, my requirement is: if data found then update else insert new record.

declare
cursor c1 is select * from factory_data.report_details order by rd_rp_id;
rec c1%rowtype;
v_check varchar2(1) := null;
begin
for rec in c1 loop
[code].......