select query

Hi,

I am having a table as temp_customers with columns like personid etc. while i execute the below procedure I receive the error as "invalid relational operator" in the query.

CREATE OR REPLACE procedure customer_detail
IS

v_refresh varchar2(500);
CURSOR get_org IS
SELECT cst_ref
FROM temp_org1;

begin

for x1_rec in get_org
loop
v_refresh:= 'insert into temp_table (select PERSONID from temp_customers where'|| x1_rec.cst_ref ||'is not null)';
execute immediate v_refresh;
end loop;
end;
/

could you please help me