// gets the base path of the ajax call, corrected for protocol.
  function ajaxBasePath() {
  	var base_path = "http://www1.subimo.com/cav4/app/hcboexp/ajax";
  	base_path = correctAddressProtocol(base_path);
  	return base_path;
  }
  /*
    Used to work around a goofiness we've run into; makes sure that if the protocol
    should be https, then it stays https, so that the Ajax call doesn't fail on
    XMLHttpRequest.open.    
  */
  function correctAddressProtocol(suspect_url) {
    //alert(suspect_url.substring(7));
    var protocol_target = parse_protocol(suspect_url);
    var protocol_actual = parse_protocol("" + window.location);
    if (protocol_target != protocol_actual) {
      return protocol_actual + suspect_url.substring(protocol_target.length);
    }
    return suspect_url;
  }
	
  // find the protocol (what's before the '//')
  function parse_protocol(url) {
    var protocol_ends = url.search("//")
    return url.substring(0,protocol_ends);
  }

	// the general server interaction method - uses Ajax to call the server with
	// the 'target' request...
  function callServer(target, handlerMethod) {
    
    req = getXMLHttpRequest();
    
    // get the test document; will populate the headers as well:-)
    req.onreadystatechange = handlerMethod;
    
	req.open("GET", target, true);
	req.send(null);
    
  }

  // the XMLHttpRequest object referenced when the handleProcessing function is used...
  var req;

  // generic handling method; calls a page-specific javascript method when ready...  
  function handleProcessing() {
  	// jumping to the landing page and jumping back quickly has caused this to be 
  	// called with a noninitialized 'req' variable - this should fix the resulting error:-)
	if (req == undefined) { return; }
  	
	if (req.readyState==4) {

      var doc_val = req.responseText;

	  // this is defined once for each page that uses Ajax, to handle it's 
	  // special case(s)
      handleAjaxResults(doc_val);
    }
  }
  
  function emptyAjaxHandler() {  
  }

  // IE and FF don't much like each other...
	function getXMLHttpRequest() {

	  var xmlhttp;
	
	  /*@cc_on
	
	  @if (@_jscript_version >= 5)
	
	    try {

	      xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
	
	    } catch (e) {
	      try {
	        xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
	      } catch (E) {
	        xmlhttp = false;
	      }
	    }
	
	  @else
	
	  xmlhttp = false;
	
	  @end @*/
	
	  if (!xmlhttp && typeof XMLHttpRequest != 'undefined') {
	    try {
	
	      xmlhttp = new XMLHttpRequest();
	
	    } catch (e) {
	      xmlhttp = false;
	    }
	  }
	
	  return xmlhttp;
	}

	// since the logout request does not use the handleProcessing() method, need to hold the
	// request object in another variable, to prevent the handling method being assigned a 
	// non-empty method from either the landing page of planQuestions.
	var logout_ajax_requester;

	// sends a logout request to the server, then closes the current window (if opened by javascript, anyway)
	function logout() {
		// send Logout to clear server session
		var logout_call = ajaxBasePath() + "/logout";
		logout_call = correctAddressProtocol(logout_call);
		var logout_req = getXMLHttpRequest();
    
	    // get the test document; will populate the headers as well:-)
	    logout_req.onreadystatechange = emptyAjaxHandler;
	    
		logout_req.open("GET", logout_call, true);
		logout_req.send(null);
		
		// conflicts with the global 'req' object used for the questions - 
		// the questions may overwrite the empty handling method, causing a 
		// stop error:  callServer(logout_call, emptyAjaxHandler);
	}