var req;
var article_dom;

function loadXMLDoc(url){
  // branch for native XMLHttpRequest object
  if (window.XMLHttpRequest) {
    req = new XMLHttpRequest();
    req.onreadystatechange = processReqChange;
    req.open("GET", url, true);
    req.send(null);
    // branch for IE/Windows ActiveX version
  } else if (window.ActiveXObject) {
    req = new ActiveXObject("Microsoft.XMLHTTP");
    if (req) {
      req.onreadystatechange = processReqChange;
      req.open("GET", url, true);
      req.send();
    }
  }
}

function processReqChange(){
  // only if req shows "complete"
  if (req.readyState == 4) {
    // only if "OK"
    if (req.status == 200) {
      article_dom=req.responseXML;
      load_conditions("a");
    } else {
      alert("There was a problem retrieving the XML data:\n" + req.statusText);
    }
  }
}
function condition_sort(a,b){
    return a["condition"] < b["condition"];
}

function load_conditions(category){
  if(category=="a"){
    var start="a";
    var end="d";
    var button=document.getElementById("condition_e");
    button.className="condition_selector_inactive";
    
    button=document.getElementById("condition_m");
    button.className="condition_selector_inactive";

    var button=document.getElementById("condition_"+category);
    button.className="condition_selector_active";
  }else if(category == "e"){
    var start="f";
    var end="l";
    var button=document.getElementById("condition_a");
    button.className="condition_selector_inactive";
    
    button=document.getElementById("condition_m");
    button.className="condition_selector_inactive";

    var button=document.getElementById("condition_"+category);
    button.className="condition_selector_active";

  }else if(category == "m"){
    var start="m";
    var end="z";
    var button=document.getElementById("condition_a");
    button.className="condition_selector_inactive";
    
    button=document.getElementById("condition_e");
    button.className="condition_selector_inactive";

    var button=document.getElementById("condition_"+category);
    button.className="condition_selector_active";
  }else{
    var start="a";
    var end="z";
  }
  
  var p_node=document.getElementById("condition_parent");
  var container=document.getElementById("condition_container");

  if(container!=null){
    p_node.removeChild(container);
  }

  container=document.createElement("div");
  container=p_node.appendChild(container);
  container.id="condition_container";
  
  //loop through articles
  var article_nodes=article_dom.documentElement.childNodes;
  var articles = new Array();
  var conditions=new Array();
  for(var i=0; i<article_nodes.length; i++){
    var condition=article_nodes[i].getAttribute("condition");
    if(condition.toLowerCase() >= start && end >= condition.substring(0,1).toLowerCase()){
	var article=new Array();
	article["id"]=article_nodes[i].getAttribute("id");
	article["condition"]=article_nodes[i].getAttribute("condition");
	article["description"]=article_nodes[i].getAttribute("description");
	articles[article["condition"].toLowerCase()]=article;
	conditions.push(article["condition"].toLowerCase());
    }
  }
  
  conditions.sort();
  for (var i=0; i< conditions.length; i++){
      var article=articles[conditions[i]];
      var node=document.createElement("div");
      node=container.appendChild(node);
      node.id=article["id"];
      //alternate background colors for links
      if (i%2){
        node.className="condition_link_container_grey";
      }else{
        node.className="condition_link_container";
      }
    //link
    var link=document.createElement("a");
    link=node.appendChild(link);
    link.className="condition_link";
    link.setAttribute("href","condition-article.html?article_id="+article["id"]);
      
    //title
    var title=document.createTextNode(article["condition"]);
    title=link.appendChild(title);
      
    //line break
    var br=document.createElement("br");
    br=node.appendChild(br);
    
    //description
    var desc=document.createTextNode(article["description"]+"  ");
    desc=node.appendChild(desc);

    //tailing link
    var link=document.createElement("a");
    link=node.appendChild(link);
    link.className="tailing_link";
    link.setAttribute("href","condition-article.html?article_id="+article["id"]);
    var ltext=document.createTextNode("more...");
    ltext=link.appendChild(ltext);

  }
}

//load up the article list
setTimeout("loadXMLDoc('condition_articles.xml.php')",500);