function getWeekDate( $year , $weeknum ){
$firstdayofyear = mktime (0,0,0,1,1, $year );
$firstweekday = date ( 'N' , $firstdayofyear );
$firstweenum = date ( 'W' , $firstdayofyear );
if ( $firstweenum ==1){
$day =(1-( $firstweekday -1))+7*( $weeknum -1);
$startdate = date ( 'Y-m-d' , mktime (0,0,0,1, $day , $year ));
$enddate = date ( 'Y-m-d' , mktime (0,0,0,1, $day +6, $year ));
} else {
$day =(9- $firstweekday )+7*( $weeknum -1);
$startdate = date ( 'Y-m-d' , mktime (0,0,0,1, $day , $year ));
$enddate = date ( 'Y-m-d' , mktime (0,0,0,1, $day +6, $year ));
return array ( $startdate , $enddate );