jQuery $.ajax alerts two times

When it loads jQuery alerts two times then after which you can't see what's under the body tag after second load.

File 1

$.ajax({
  url: "https://samplesite.com/5IIIM/ORG-CORE-API-LIB/dll.js",
  dataType: "script",
  error: function() {
    alert("System Maintenance On Going. Please try again later.");
  },
  success: function() {
    alert("Welcome!");
  }
});

File 2

$(document).ready(function() {
  $("body").load("https://samplesite.com/5IIIM/ORG-CORE-API-LIB/5IIIMdll-pagebody.html");
});