/*** AJAX ***/

var ajax_req;  // OBJETO XML (ajax)
var ajax_result='';
var ajax_external='';
function loadXMLDoc(url) {
    // branch for native XMLHttpRequest object
    if (window.XMLHttpRequest) {
        ajax_req = new XMLHttpRequest();
        ajax_req.onreadystatechange = processReqChange;
        ajax_req.open("GET", url, true);
        ajax_req.setRequestHeader("Referer", window.location);
        ajax_req.send(null);
    // branch for IE/Windows ActiveX version
    } else if (window.ActiveXObject) {
        ajax_req = new ActiveXObject("Microsoft.XMLHTTP");
        if (ajax_req) {
            ajax_req.onreadystatechange = processReqChange;
            ajax_req.open("GET", url, true);
            ajax_req.send();
        }
    }
}

// FUNCION Q SE LLAMA EN CADA PETICION AL AJAX
function processReqChange() {
	// only if ajax_req shows "complete"
	if (ajax_req.readyState == 4) {
		// si "OK"
		if (!ajax_req.status || (ajax_req.status == 200)) {
			// si anda todo bien, proceso...
			if (ajax_reading) {
				//cargo el resultado de la url
				ajax_result=ajax_req.responseText;
			} else {
				ajax_result='ERROR:busy';
			}
		} else {
			ajax_result='ERROR:'+ajax_req.statusText;
		}
		ajax_reading = false;
		if (ajax_external!='')
			eval(ajax_external);
	}
	return false;
}

var ajax_reading = false; // SEMAFORO!
function LoadURL(url, external) {
	ajax_reading = true;
	ajax_result='';
	
	var d = new Date()
	var uID = '' + d.getDate()+d.getMonth() +1+d.getFullYear()+d.getHours()+d.getMinutes()+d.getSeconds()+Math.random();
	if (url.indexOf('?')>0)
		url  = url+'&uID='+uID;
	else
		url  = url+'?uID='+uID;

    // Add the session pid
    url = url + "&PHPSESSID=b94ddd4c97a9ae800d9312b9b2ea49e2";

	ajax_external=external;
	try {
	   loadXMLDoc(url);
        }
        catch (e) {
            ajax_result = "ERROR:not connected";
        }
	return ajax_result;
}

var variables;
        
var layerObject, layerDir;
var layerHTML;
var layerScripts;
var layerLoadList;
var layerLoadListParams;    // GET parameters

var layerDrawn = false;
var layerExecuted = false;
        
// "Constructor"
variables = Array();
layerLoadList = Array();
layerLoadListParams = Array();
layerHTML = Array();
layerScripts = Array();
    
function setVar(varName, varValue) {
    variables[varName] = varValue;
}
    
function getVar(varName) {
    return variables[varName];
}

function remVar(varName) {
    variables[varname] = null;
}
    
function saveHTTPVar(varName) {
    // Get cookies staten
    var parts, parties, key, changed;
    
    // Flag for checking whether value is alredy checked.
    changed = false;
    
    // Break
    parts = document.cookie.split(/;/);
    for (key in parts) {
        parties = parts.split(/=/);
        if (parties[0] == varName) {
            parties[1] = variables[varName];
            parts = parties.join("=");
            changed = true;
        }
    }
    
    if (changed)
        document.cookie = parts.join(";");
    else
        if (document.cookie)
            document.cookie += ";" + varName + "=" + variables[varName];
        else
            document.cookie = varName + "=" + variables[varName];
            
}

// Synchronous system call, whith callback function
function sysCall(url, func) {
    
    if (ajax_reading)
        throw 'AjaxBusy';
        
    LoadURL(url, func);
    
}
    
/*** Layers ***/
function setLayerObject(id) {
    layerObject = id;            
}
    
function setLayerDir(url) {
    layerDir = url;
}
    
function layerLoad(layerName, getParams) {
    if (!layerLoadList)
        layerLoadList = Array();
    layerLoadList.push(layerName);
    if (getParams != "")
        layerLoadListParams[layerName] = getParams;
    
    loadAllLayers();
}
    
function layerDraw(layerName) {
    if (document.getElementById(layerObject))
        document.getElementById(layerObject).innerHTML = layerHTML[layerName];

    layerDrawn = layerName;

}
    
function layerExecute(layerName) {

    layerExecuted = layerName;

    eval(layerScripts[layerName]);

    main();

}

/*** FUNCIONES INTERNAS ***/    

function loadAllLayers() {
    var getParams;
    
    if (ajax_reading)
        return;

    if (layerLoadList.length) {
        getParams = layerLoadListParams[layerLoadList[0]] ? "?" + layerLoadListParams[layerLoadList[0]] : "";
        LoadURL(layerDir + "/" + layerLoadList[0] + getParams, "layerHTMLLoaded(\"" + layerLoadList[0] + "\")");
    }
        
}

function layerHTMLLoaded(layerName) {
    var getParams;
    
    layerHTML[layerName] = ajax_result;
    
    getParams = layerLoadListParams[layerLoadList[0]] ? "?" + layerLoadListParams[layerLoadList[0]] : "";
    LoadURL(layerDir + "/" + layerName + ".js" + getParams, "layerJSLoaded(\"" + layerName + "\")");
    
}

function layerJSLoaded(layerName) {
    var i;
    
    layerScripts[layerName] = ajax_result;
    
    for (i in layerLoadList) if (layerLoadList[i] == layerName) {
        layerLoadList.splice(i, 1);
        break;
    }
 
    loadAllLayers();
    layerLoaded(layerName);
           
}

function layerIsLoaded(layerName) {
    return layerScripts[layerName] != null;
}