> https://apis.tdameritrade.com/apps/100/LogIn?source=#sourceID#&version=#version
>
> POST DATA
userid=#userid#&password=#password#&source=#sourceID#&version=#version

function logIn() {
  // check if car is reachable
  var fetch_string="https://apis.tdameritrade.com/apps/300/LogIn?source=MySourceID#&version=1.0";
  var options = {
   'method' : 'post',
    "headers" : {
      "userid" : "MyUser",
      "password" : "MyPassword",
      "source" : "MySourceID",
      "version" : "1.0"
    }
  };
   var response = UrlFetchApp.fetch(fetch_string, options);
   var document = XmlService.parse(response)
  Logger.log(document);
debugger;
 }

function getData(task){
    Source=valIs('SourceID'); User=valIs('Username'); Pass=valIs('Password');
    if(Source=='' || User=='' || Pass==''){ alert('Need User Info'); return false; }
    url='https://apis.tdameritrade.com/apps/'; src='source='+Source;
    Ajax=new XMLHttpRequest();
    if(task=='login'){
        data=src+'&version=1.0';
        url+='100/LogIn?'+data;
        data+='&userid='+User+'&password='+Pass;
        add('tracking','URL: '+url+'<br>Data: '+data+'<br><br>');
        Ajax.open('POST', url, true);
        Ajax.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
        Ajax.send(data);