handling ajax failures

ajaxscript.js

$.ajax({}).

.done(

  //200 returned but not well formed JSON string
  if(!data.status) {return false;}
  
  //200 with well formed JSON & an error
  if(data.status === "fail") {
    alert(data.message);
    return false;
  }
  
  //200 with success
  
  alert('returned succesfully');
  return true;

)

.fail(
  //status code above 400 returned
  alert(xhr.status);
  return false;
);