xmlHttp = false;
                
try {
        xmlHttp = new XMLHttpRequest();
} catch(Microsoft1) {
        try {
                xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
        } catch(failed) {
                xmlHttp = false;
        }
}
                
if(!xmlHttp) {
        alert("Error: Could Not Initialize XMLHttpRequest()!\r\n\r\nJavaScript must be enabled to view this page.");
}

xmlHttp = false;
                
try {
        xmlHttp = new XMLHttpRequest();
} catch(Microsoft1) {
        try {
                xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
        } catch(failed) {
                xmlHttp = false;
        }
}
                
if(!xmlHttp) {
        alert("Error: Could Not Initialize XMLHttpRequest()!\r\n\r\nJavaScript must be enabled to view this page.");
}

/* 
        XmlHttpRequest Wrapper
        Version 1.2.2
        29 Jul 2005 
        adamv.com/dev/
*/

var Http = {
        ReadyState: {
                Uninitialized: 0,
                Loading: 1,
                Loaded:2,
                Interactive:3,
                Complete: 4
        },
                
        Status: {
                OK: 200,
                
                Created: 201,
                Accepted: 202,
                NoContent: 204,
                
                BadRequest: 400,
                Forbidden: 403,
                NotFound: 404,
                Gone: 410,
                
                ServerError: 500
        },
                
        Cache: {
                Get: 1,
                GetCache: 2,
                GetNoCache: 3,
                FromCache: 4
        },
        
        Method: {Get: "GET", Post: "POST", Put: "PUT", Delete: "DELETE"},
        
        enabled: false,
        logging: false,
        _get: null,     // Reference to the XmlHttpRequest object
        _cache: new Object(),
        
        Init: function(){
                Http._get = Http._getXmlHttp()
                Http.enabled = (Http._get != null)
                Http.logging = (window.Logging != null);
        },
        
        _getXmlHttp: function(){
        /*@cc_on @*//*@if (@_jscript_version >= 5)
                try { return new ActiveXObject("Msxml2.XMLHTTP"); } 
                catch (e) {} 
                try { return new ActiveXObject("Microsoft.XMLHTTP"); } 
                catch (e) {} 
        @end @*/
                try { return new XMLHttpRequest();}
                catch (e) {}

                return null;
        },

/*
        Params:
                url: The URL to request. Required.
                cache: Cache control. Defaults to Cache.Get.
                callback: onreadystatechange function, called when request is completed. Optional.
                method: HTTP method. Defaults to Method.Get.
*/
        get: function(params, callback_args){   
                if (!Http.enabled) throw "Http: XmlHttpRequest not available.";
                
                var url = params.url;
                if (!url) throw "Http: A URL must be specified";
                                
                var cache = params.cache || Http.Cache.Get;
                var method = params.method || Http.Method.Get;
                var callback = params.callback;
                
                if ((cache == Http.Cache.FromCache) || (cache == Http.Cache.GetCache))
                {
                        var in_cache = Http.from_cache(url, callback, callback_args)

                        if (Http.logging){
                                Logging.log(["Http: URL in cache: " + in_cache]);
                        }

                        if (in_cache || (cache == Http.Cache.FromCache)) return in_cache;
                }
                
                if (cache == Http.Cache.GetNoCache)
                {
                        var sep = (-1 < url.indexOf("?")) ? "&" : "?"      
                        url = url + sep + "__=" + encodeURIComponent((new Date()).getTime());
                }
        
                // Only one request at a time, please
                if ((Http._get.readyState != Http.ReadyState.Uninitialized) && 
                        (Http._get.readyState != Http.ReadyState.Complete)){
                        this._get.abort();
                        
                        if (Http.logging){
                                Logging.log(["Http: Aborted request in progress."]);
                        }
                }
                
                Http._get.open(method, url, true);

                Http._get.onreadystatechange =  function() {
                        if (Http._get.readyState != Http.ReadyState.Complete) return;
                        
                        if (Http.logging){
                                Logging.log(["Http: Returned, status: " + Http._get.status]);
                        }

                        if ((cache == Http.Cache.GetCache) && (Http._get.status == Http.Status.OK)){
                                Http._cache[url] = Http._get.responseText;
                        }
                        
                        if (callback_args == null) callback_args = new Array();

                        var cb_params = new Array();
                        cb_params.push(Http._get);
                        for(var i=0;i<callback_args.length;i++)
                                cb_params.push(callback_args[i]);
                                
                        callback.apply(null, cb_params);
                }
                
                if(Http.logging){
                        Logging.log(["Http: Started\n\tURL: " + url + "\n\tMethod: " + method + "; Cache: " + Hash.keyName(Http.Cache,cache)])
                }
                
                Http._get.send(params.body || null);
        },
        
        from_cache: function(url, callback, callback_args){
                var result = Http._cache[url];
                
                if (result != null) {
                        var response = new Http.CachedResponse(result)
                        
                        var cb_params = new Array();
                        cb_params.push(response);
                        for(var i=0;i<callback_args.length;i++)
                                cb_params.push(callback_args[i]);
                                                        
                        callback.apply(null, cb_params);
                                
                        return true
                }
                else
                        return false
        },
        
        clear_cache: function(){
                Http._cache = new Object();
        },
        
        is_cached: function(url){
                return Http._cache[url]!=null;
        },
        
        CachedResponse: function(response) {
                this.readyState = Http.ReadyState.Complete
                this.status = Http.Status.OK
                this.responseText = response
        }    
}

Http.Init()

function json_response(response){
        var js = response.responseText;
        try{
                return eval(js); 
        } catch(e){
                if (Http.logging){
                        Logging.logError(["json_response: " + e]);
                }
                else{
                        alert("Error: " + e + "\n" + js);
                }
                return null;
        }
}

function getResponseProps(response, header){
        try {
                var s = response.getResponseHeader(header || 'X-Ajax-Props');
                if (s==null || s=="")
                        return new Object()
                else
                        return eval("o="+s)
        } catch (e) { return new Object() }
}

Caching Options
These options only make sense to use with the GET method. POST operations should not be cached.

Http.Cache.Get
Perform a normal request, and do not add the result to the local cache. Note: on IE, requesting the same URL via GET multiple times will cause IE to cache the result internally.
Http.Cache.GetCache
Perform a request and cache the result if sucessful. If the requested URL's response is already cached locally, do not perform the server request.
Http.Cache.GetNoCache
Perform a request and add a time-based variable to the querystring to force IE not to cache the result. The result is not placed in the local cache.
Http.Cache.FromCache
If the requested URL's response has already been cached, call the supplied callback on the locally cached version. Http.get will return true or false based on whether or not the response is in the cache.

// description of your code here

JS Source

/*
 * Edit In Place
 * http://josephscott.org/code/js/eip/
 *
 * Version: 0.2.0
 * License: http://josephscott.org/code/js/eip/license.txt
 */
EditInPlace = function() { };
EditInPlace.settings = function(set) {
        var settings = {
                id:                             false,
                save_url:               false,
                css_class:              'eip_editable',
                savebutton:             'eip_savebutton',
                cancelbutton:   'eip_cancelbutton',
                saving:                 'eip_saving',
                type:                   'text',
                orig_text:              false
        };

        for(var i in set) { settings[i] = set[i]; }

        return($H(settings));
};

EditInPlace.formField = function(set) {
        var field = '';
        set['orig_text'] = $(set['id']).innerHTML;

        if(set['type'] == 'text') {
                var size = set['orig_text'].length + 10;
                if(size >= 100) { size = 100; }
                if(set['size']) { size = set['size']; }

                field = '/>';
        }
        else if(set['type'] == 'textarea') {
                var cols = 50;
                if(set['cols']) { cols = set['cols']; }
                var rows = (set['orig_text'].length / cols) + 3;
                if(set['rows']) { rows = set['rows']; }

                field = '<span id="' + set['id'] + '_editor"><textarea id="'
                        + set['id'] + '_edit" class="' + set['css_class'] + '" name="'
                        + set['id'] + '_edit" rows="' + rows + '" cols="'
                        + cols + '">' + set['orig_text'] + 'textarea>';
        }

        return(field);
};

EditInPlace.formButtons = function(set) {
        return(
                '
/><span><input id="' + set['id'] + '_save" class="'
                + set['savebutton'] + '" type="button" value="SAVE" /> OR '
                + '<input id="' + set['id'] + '_cancel" class="' 
                + set['cancelbutton'] + '" type="button" value="CANCEL" />'
                + 'span></span>'
        );
};

EditInPlace.setEvents = function(set) {
        Event.observe(
                set['id'],
                'mouseover',
                function() { Element.addClassName(set['id'], set['css_class']); },
                false
        );
        Event.observe(
                set['id'],
                'mouseout',
                function() { Element.removeClassName(set['id'], set['css_class']); },
                false
        );
        Event.observe(
                set['id'],
                'click',
                function() {
                        Element.hide(set['id']);

                        var field = EditInPlace.formField(set);
                        var button = EditInPlace.formButtons(set);

                        new Insertion.After(set['id'], field + button);
                        Field.focus(set['id'] + '_edit');

                        Event.observe(
                                set['id'] + '_save',
                                'click',
                                function() { EditInPlace.saveChanges(set); },
                                false
                        );
                        Event.observe(
                                set['id'] + '_cancel',
                                'click',
                                function() { EditInPlace.cancelChanges(set); },
                                false
                        );
                },
                false
        );
};

EditInPlace.saveComplete = function(t, set) {
        $(set['id']).innerHTML = t.responseText;
};

EditInPlace.saveFailed = function(t, set) {
        $(set['id']).innerHTML = set['orig_text'];
        Element.removeClassName(set['id'], set['css_class']);
        alert('Failed to save changes.');
};

EditInPlace.saveChanges = function(set) {
        var new_text = escape($F(set['id'] + '_edit'));
        $(set['id']).innerHTML = 
                '<span class="' + set['saving'] + '">Saving ...span>';

        Element.remove(set['id'] + '_editor');
        Element.show(set['id']);

        var params = 'id=' + set['id'] + '&content=' + new_text;
        var ajax_req = new Ajax.Request(
                set['save_url'],
                {
                        method: 'post',
                        postBody: params,
                        onSuccess: function(t) { EditInPlace.saveComplete(t, set); },
                        onFailure: function(t) { EditInPlace.saveFailed(t, set); }
                }
        );
};

EditInPlace.cancelChanges = function(set) {
        Element.remove(set['id'] + '_editor');
        Element.removeClassName(set['id'], set['css_class']);
        Element.show(set['id']);
}

EditInPlace.makeEditable = function(args) {
        EditInPlace.setEvents(EditInPlace.settings(args));
}

HTML source

<html>
<head><title>Ajax Edit In Place (EIP) Exampletitle>







"example.html">Ajax Edit In Place (EIP) Example


"editme">AJAX edit in place like flickr.






"anotheredit">If you want room for more text you can use a textarea to edit instead.

PHP source

<?php
        $id = $_POST["id"];
        $content = $_POST["content"];
        print(htmlspecialchars($content));
?>

Wrapper function for constructing a request object.
Parameters:
reqType: The HTTP request type, such as GET or POST.
url: The URL of the server program.
asynch: Whether to send the request asynchronously or not.

function httpRequest(reqType,url,asynch) {

        // Mozilla-based browsers
        if (window.XMLHttpRequest) {
                request = new XMLHttpRequest();
        } else if (window.ActiveXObject) {
                request = new ActiveXObject("Msxml2.XMLHTTP");
                if (!request) {
                        request = new ActiveXObject("Microsoft.XMLHTTP");
                }
        }
        
        // Request could still be null if neither ActiveXObject
        //   initialization succeeded
        if (request) {
                initReq(reqType,url,asynch);
        } else {
                alert("Your browser does not permit the use of all " +
                        "of this application's features!");
        }

}

Initialize a request object that is already constructed.

function initReq(reqType,url,asynch) {
        // Specify the function that will handle the HTTP response
        request.onreadystatechange = handleResponse;
        request.open(reqType,url,bool);
        request.send(null);
}

// javascript to go into head of document or external .js file

function ahah(url, target) {
  document.getElementById(target).innerHTML = ' Fetching data...';
  if (window.XMLHttpRequest) {
    req = new XMLHttpRequest();
  } else if (window.ActiveXObject) {
    req = new ActiveXObject("Microsoft.XMLHTTP");
  }
  if (req != undefined) {
    req.onreadystatechange = function() {ahahDone(url, target);};
    req.open("GET", url, true);
    req.send("");
  }
}  

function ahahDone(url, target) {
  if (req.readyState == 4) { // only if req is "loaded"
    if (req.status == 200) { // only if "OK"
      document.getElementById(target).innerHTML = req.responseText;
    } else {
      document.getElementById(target).innerHTML=" AHAH Error:\n"+ req.status + "\n" +req.statusText;
    }
  }
}

function load(name, div) {
        ahah(name,div);
        return false;
}

// call code with the name of the external file and the id of the div you want to put the content into

<a href="file1.html" onclick="load('file1.html','content');return false;">File 1a>

// this is a custom function that simplifies creating an ajax object

function(url, complete, form, params) {
  params = params ? $H(params).toQueryString() : '';
  if (!complete) complete = function(r){};
  if (form)      params   = Form.serialize(form) + '&' + params;
  new Ajax.Request(url, 
    { asynchronous:true,
      evalScripts:true, 
      onComplete: function(r) { complete(r.responseText); },
      parameters:params
    });
}

Firefox doesn't do a lot of simultaneous AJAX (or any kind of HTTP) requests. IE caps it at 2, too. This will allow you to test your XHR overload scripts, or just load pages faster in general.

1. Go to "about:config"
2. Find and edit the following
* network.http.pipelining=false
* network.http.pipelining.maxrequests=4
* network.http.proxy.pipeline=false
3. Make the false's true; I set my maxrequests at 20

// description of your code here

function simpletogglediv(whichLayer)
{
         var theElementStyle = document.getElementById(whichLayer); 

        if(theElementStyle.style.display == "block")
        { 
                theElementStyle.style.display = "none";  
                 
        }
        else
        { 
                theElementStyle.style.display = "block"; 
        }
}