Application Express :: Tabular Form Select List Validation

I use apex 4.1..I have a tabular form a select like this

select
"STRATEGYID",
"STRATEGYID" STRATEGYID_DISPLAY,
"STRATEGYNAME",
"ISAVTIVE",
"STRATEGYSTARTYEAR",
"STRATEGYSTOPTYEAR",
"STRATEGYTYPEID"
from "#OWNER#"."STRATEGY"
where ISAVTIVE = 1STRATEGYSTARTYEAR and STRATEGYSTOPTYEAR as a Select List contain a value of year

I select from LOV like this
select y l, y v
from (select extract(year from sysdate) + rownum - 1y from dual connect by rownum <= 51)and

I have to Validate STRATEGYSTARTYEAR must Less than STRATEGYSTOPTYEAR