jquery-callback

callback 
javascript step by step , 

A callback function is executed after the current effect is finished.

e.g.: $(selector).hide(speed,callback);

$("button").click(function(){
  $("p").hide("slow",function(){
    alert("The paragraph is now hidden");
  });
});


Example without Callback

$("button").click(function(){
  $("p").hide(1000);
  alert("The paragraph is now hidden");
});