var _ms_XMLHttpRequest_ActiveX = "";
var _ajax;                           // Reference to a global XMLHTTPRequest object for some of the samples
var _logger = true;                  // write output to the Activity Log
var _status_area;                    // will point to the area to write status messages to

// From prototype.js @ www.conio.net | Returns an object reference to one or more strings
// ignore the fact that there are no arguments to this method -- javascript doesn't care how many you send (not strongly typed)
// The method checks the actual # of arguments -- returns a single object or an array
function $() {
    var elements = new Array();

    for (var i = 0; i < arguments.length; i++) {
        var element = arguments[i];

        if (typeof element == 'string')
            element = document.getElementById(element);

        if (arguments.length == 1)
            return element;

        elements.push(element);
    }

    return elements;
}

// If you plan on doing anything outside of North America, then you'd better encode the things you pass back and forth
// the escape() method in Javascript is deprecated -- should use encodeURIComponent if available
function encode( uri ) {
    if (encodeURIComponent) {
        return encodeURIComponent(uri);
    }

    if (escape) {
        return escape(uri);
    }
}

function decode( uri ) {
    uri = uri.replace(/\+/g, ' ');

    if (decodeURIComponent) {
        return decodeURIComponent(uri);
    }

    if (unescape) {
        return unescape(uri);
    }

    return uri;
}


function AJAXRequest( method, url, data, process, async, dosend) {
    // self = this; creates a pointer to the current function
    // the pointer will be used to create a "closure". A closure
    // allows a subordinate function to contain an object reference to the
    // calling function. We can't just use "this" because in our anonymous
    // function later, "this" will refer to the object that calls the function 
    // during runtime, not the AJAXRequest function that is declaring the function
    // clear as mud, right?
    // Java this ain't
    
    var self = this;

    // check the dom to see if this is IE or not
    if (window.XMLHttpRequest) {
	// Not IE
        self.AJAX = new XMLHttpRequest();
    } else if (window.ActiveXObject) {
	// Hello IE!
        // Instantiate the latest MS ActiveX Objects
        if (_ms_XMLHttpRequest_ActiveX) {
            self.AJAX = new ActiveXObject(_ms_XMLHttpRequest_ActiveX);
        } else {
	    // loops through the various versions of XMLHTTP to ensure we're using the latest
	    var versions = ["Msxml2.XMLHTTP.7.0", "Msxml2.XMLHTTP.6.0", "Msxml2.XMLHTTP.5.0", "Msxml2.XMLHTTP.4.0", "MSXML2.XMLHTTP.3.0", "MSXML2.XMLHTTP",
                        "Microsoft.XMLHTTP"];

            for (var i = 0; i < versions.length ; i++) {
                try {
		    // try to create the object
		    // if it doesn't work, we'll try again
		    // if it does work, we'll save a reference to the proper one to speed up future instantiations
                    self.AJAX = new ActiveXObject(versions[i]);

                    if (self.AJAX) {
                        _ms_XMLHttpRequest_ActiveX = versions[i];
                        break;
                    }
                }
                catch (objException) {
                // trap; try next one
                } ;
            }

            ;
        }
    }
    
    // if no callback process is specified, then assing a default which executes the code returned by the server
    if (typeof process == 'undefined' || process == null) {
        process = function() { };
    }

    self.process = process;

    // create an anonymous function to log state changes
    self.AJAX.onreadystatechange = function( ) {
        //logger("AJAXRequest Handler: State =  " + self.AJAX.readyState);
        self.process(self.AJAX);
    }

    // if no method specified, then default to POST
    if (!method) {
        method = "POST";
    }

    method = method.toUpperCase();

    if (typeof async == 'undefined' || async == null) {
        async = true;
    }

    self.AJAX.open(method, url, async);

    if (method == "POST") {
        self.AJAX.setRequestHeader("Connection", "close");
        self.AJAX.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
        self.AJAX.setRequestHeader("Method", "POST " + url + "HTTP/1.1");
    }

    // if dosend is true or undefined, send the request
    // only fails is dosend is false
    // you'd do this to set special request headers
    if ( dosend || typeof dosend == 'undefined' ) {
	    if ( !data ) data=""; 
	    self.AJAX.send(data);
    }
    return self.AJAX;
}


function getFieldsForTable( table, target ) {
	var fields_div = $('fields_div');
    fields_div.style.visibility = 'visible';
    return new AJAXRequest("post", "/ed/form.php", "mode=ajax&table=" + encode(table), processGetFieldsByTable);
}

function processGetFieldsByTable( myAJAX ) {
    if (myAJAX.readyState == 4) {
        if (myAJAX.status == 200) {
            var encodedHtml = myAJAX.responseText;
          	//alert(encodedHtml);
						var html = JSON.parse(encodedHtml);
            //alert(html);
				}
        var div = document.getElementById("fields_div");
        if (div) {
	                div.innerHTML = html;
	                div.style.visibility = "visible"
	      } else {
            alert("There was a problem retrieving the XML data:\n" + myAJAX.statusText);
        }
    }
}

function ajaxDelete(action, dbId, htmlId, lang) {
	if(confirm(lang == "fr" ? "Êtes-vous certain de vouloir supprimer cet élément?" : "Are you sure you wish to delete this element?")) {
		var ajax = new AJAXRequest("post", "/ed/ajaxActions.php", "action=" + encode(action) + "&id=" + encode(dbId), null, false);
		if(ajax.responseText == "OK") {
			var nodeToDelete = document.getElementById(htmlId);
			nodeToDelete.parentNode.removeChild(nodeToDelete);
		}
		else {
			alert(ajax.responseText);
		}
	}
}

function ajaxSwap(action, dbId1, dbId2, htmlId1, htmlId2) {
	var ajax = new AJAXRequest("post", "/ed/ajaxActions.php", "action=" + encode(action) + "&id1=" + encode(dbId1) + "&id2=" + encode(dbId2), null, false);
	if(ajax.responseText == "OK") {
		swapNodes(document.getElementById(htmlId1), document.getElementById(htmlId2));
	}
	else {
		alert(ajax.responseText);
	}
}