var ajaxobj;

function ajax_request() {
  document.domain="systeminmerge.com";
  if(navigator.appName == "Microsoft Internet Explorer") {
    ajaxobj = new ActiveXObject("Microsoft.XMLHTTP");
  } else {
    ajaxobj = new XMLHttpRequest();
  }
  
  ajaxobj.open('get', 'http://www.systeminmerge.com/plugins/optin.php');
  ajaxobj.onreadystatechange = ajax_response;
  ajaxobj.send(null);
}

function ajax_response() {
  if(ajaxobj.readyState == 4) {
    alert(ajaxobj.responseText);
  }
}