Repeat code every 4 seconds

I want repeat this code every 4 seconds, how i can do it with javascript or jquery easly ? Thanks. :)

$.get("request2.php", function(vystup){
   if (vystup !== ""){
      $("#prompt").html(vystup);
      $("#prompt").animate({"top": "+=25px"}, 500).delay(2000).animate({"top": "-=25px"}, 500).delay(500).html("");
    }
});