function cta_serve(){
  var now=new Date();
  var head=document.getElementsByTagName("head")[0];

  //load up the cta delivery script
  var page_view_script=document.createElement("script");
  page_view_script.type="text/javascript";

  //start building query string
  var q_string='page='+document.location+'&referer='+document.referrer;

  //look for sub system
  var subsystem=document.getElementById("sub_system");
  if(subsystem){
    q_string +="&subsystem_id="+subsystem.getAttribute("subsystem_id");
    q_string +="&subsystem_user_id="+subsystem.getAttribute("user_id");
  }
  
  //put time on end to prevent cache
  q_string +="&"+now.getTime();

  page_view_script.src='http://cta.andii.com/scripts/page_view.js.php?'+q_string;
  head.appendChild(page_view_script);

  //check for ncerx login area
  var login=document.getElementById("ncerx_login");
  if(login){
    var login_script=document.createElement("script");
    login_script.type="text/javascript";
    var random=Math.floor(Math.random()*1000);
    login_script.src='http://cta.andii.com/scripts/ncerx_login.js.php?'+random;
    head.appendChild(login_script);
  }
}