PHP Sleep 함수 구현

<script language="JavaScript">
<!--
function sleep(sec) {
    var now = new Date();
    var exitTime = now.getTime() + (sec*1000);
    while (true) {
          now = new Date();
          if (now.getTime() > exitTime) return;
    }
}

sleep(5);
alert('메롱');
//-->
</script>

출처 : PHPSCHOOL 지우님