var url = 'http://www.cfsinnovation.com/ajax-request.php';
var _my_ajax__current_form;
var _my_ajax__current_name;
var _my_ajax__handler_function;
var _my_ajax__parameter;


/**
 * Run the handler, with the form name, the element name, and the
 * request parameter object.
 */
function AjaxServerResponse(){
  if(http.readyState == 4){
    if(http.status == 200){
      var response_xml = (new DOMParser()).parseFromString(http.responseText, "text/xml");
      _my_ajax__handler_function(_my_ajax__current_form, _my_ajax__current_name, _my_ajax__parameter, response_xml);
    }
    else{
      alert("There was an error retrieving the XML data packet: " + http.statusText);
    }
  }
}

/**
 * Call this function with...
 *  1 - The name of the form being called from.
 *  2 - The name of the element being called from.
 *  3 - The name of the response handler function.
 *  4 - The name of the server side request handler.
 *  5 - The parameter object, where each data member is passed
 *     as a post parameter.
 */
function AjaxServerRequest(this_form, this_name, this_handler_function,
    this_ajax_handler, this_parameter){
  /* Set identifing flag. */
  var argument = 'ajax__request_type=1';
  /* Set the process control parameters, and encode as URL argument. */
  this_parameter.ajax__form = this_form;
  this_parameter.ajax__handler = this_ajax_handler;
  for(var parameter in this_parameter){
    argument += ("&" + parameter + '=' + escape(this_parameter[parameter]));
  } 
  /* Load the response. */
  http.open("post", url);
  http.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
  _my_ajax__current_form = this_form;
  _my_ajax__current_name = this_name;
  _my_ajax__handler_function = this_handler_function;
  _my_ajax__parameter = this_parameter;
  http.onreadystatechange = AjaxServerResponse;
  http.send(argument);
}


// The getHTTPObject() functon, courtesy of this page:
//    http://www.webpasties.com/xmlHttpRequest/step3.html
// Usage: 
//   var http = getHTTPObject(); // We create the HTTP Object
function getHTTPObject() {
  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;
}

/* * * Some helper functions for modules below..... * * */

/* Set a form element if data is available in the named tag. */
function xml_response_suggest_form(form, field, tag_name, xml){
  var tag_xml = xml.getElementsByTagName(tag_name)[0];
  if(tag_xml != null && tag_xml.firstChild != null && document.forms[form][field] != null){
    document.forms[form][field].value = tag_xml.firstChild.data;    
  }
}

/* Set a form element, from data in the named tag. If tag is empty or
 * missing, the form is cleared. */
function xml_response_set_form(form, field, tag_name, xml){
  var tag_xml = xml.getElementsByTagName(tag_name)[0];
  if(document.forms[form][field] == null){
    return;
  }
  if(tag_xml != null && tag_xml.firstChild != null && document.forms[form][field] != null){
    document.forms[form][field].value = tag_xml.firstChild.data;    
  }
  else{
    document.forms[form][field].value = '';
  }    
}


// We create the HTTP Object
var http = getHTTPObject();