diff --git a/phpgwapi/inc/class.egw_json.inc.php b/phpgwapi/inc/class.egw_json.inc.php
index a40d50b329..758653240c 100644
--- a/phpgwapi/inc/class.egw_json.inc.php
+++ b/phpgwapi/inc/class.egw_json.inc.php
@@ -184,9 +184,10 @@ class egw_json_response
 	 */
 	public function sendResult()
 	{
-		$this->sendHeader();
+		$inst = self::get();
 
-		echo $this->getJSON();
+		$inst->sendHeader();
+		echo $inst->getJSON();
 	}
 
 	/**
@@ -202,7 +203,7 @@ class egw_json_response
 	 */
 	protected function addGeneric($key, $data)
 	{
-		$this->responseArray[] = array(
+		self::get()->responseArray[] = array(
 			'type' => $key,
 			'data' => $data,
 		);
@@ -218,10 +219,11 @@ class egw_json_response
 	public function data($data)
 	{
 		/* Only allow adding the data response once */
-		if (!$this->hasData)
+		$inst = self::get();
+		if (!$inst->hasData)
 		{
-			$this->addGeneric('data', $data);
-			$this->hasData = true;
+			$inst->addGeneric('data', $data);
+			$inst->hasData = true;
 		}
 		else
 		{
@@ -317,6 +319,8 @@ class egw_json_response
 	 * Redirect to given url
 	 *
 	 * @param string $url
+	 * @param boolean $global specifies whether to redirect the whole framework
+	 * or only the current application
 	 */
 	public function redirect($url, $global = false)
 	{
@@ -330,6 +334,43 @@ class egw_json_response
 		}
 	}
 
+	/**
+	 * Displays an error message on the client
+	 */
+	public function error($msg)
+	{
+		if (is_string($msg))
+		{
+			$this->addGeneric('error', $msg);
+		}
+	}
+
+	/**
+	 * Includes the given CSS file. Every url can only be included once.
+	 *
+	 * @param string $url specifies the url to the css file to include
+	 */
+	public function includeCSS($url)
+	{
+		if (is_string($url))
+		{
+			$this->addGeneric('css', $url);
+		}
+	}
+
+	/**
+	 * Includes the given JS file. Every url can only be included once.
+	 *
+	 * @param string $url specifies the url to the css file to include
+	 */
+	public function includeScript($url)
+	{
+		if (is_string($url))
+		{
+			self::get()->addGeneric('js', $url);
+		}
+	}
+
 	/**
 	 * Returns the actual JSON code generated by calling the above "add" function.
 	 *
@@ -337,8 +378,10 @@ class egw_json_response
 	 */
 	public function getJSON()
 	{
+		$inst = self::get();
+
 		/* Wrap the result array into a parent "response" Object */
-		$res = array('response' => $this->responseArray);
+		$res = array('response' => $inst->responseArray);
 
 		return json_encode($res);	//PHP5.3+, JSON_HEX_TAG | JSON_HEX_APOS | JSON_HEX_QUOT | JSON_HEX_AMP);
 	}
@@ -348,7 +391,9 @@ class egw_json_response
 	 */
 	public function __destruct()
 	{
-		$this->sendResult();
+		//Only send the response if this instance is the singleton instance
+		if ($this == self::get())
+			$this->sendResult();
 	}
 }
 
@@ -382,7 +427,17 @@ class egw_json_response
 		$args = func_get_args();
 		$func = array_shift($args);
 
-		$this->script("window['".$func."'].apply(window, ".json_encode($args).");");
+		$this->script("try{window['".$func."'].apply(window, ".json_encode($args).");} catch(e) {_egw_json_debug_log(e);}");
+	}
+
+	public function addIncludeCSS($url)
+	{
+		$this->includeCSS($url);
+	}
+
+	public function addIncludeScript($url)
+	{
+		$this->includeScript($url);
 	}
 
 	public function getXML()
diff --git a/phpgwapi/js/egw_json.js b/phpgwapi/js/egw_json.js
index 7cee892ca6..a479dabf64 100644
--- a/phpgwapi/js/egw_json.js
+++ b/phpgwapi/js/egw_json.js
@@ -116,15 +116,24 @@ function egw_json_encode(input)
 }
 
 
-/* The constructor of the egw_json_request class.
+/**
+ * Some variables needed to store which JS and CSS files have already be included
+ */
+var egw_json_files = {};
+
+/** The constructor of the egw_json_request class.
  * @param string _menuaction the menuaction function which should be called and which handles the actual request
  * @param array _parameters which should be passed to the menuaction function.
-*/
-function egw_json_request(_menuaction, _parameters)
+ */
+function egw_json_request(_menuaction, _parameters, _context)
 {
 	//Copy the supplied parameters
 	this.menuaction = _menuaction;
 
+	this.context = window.document;
+	if (typeof _context != 'undefined')
+		this.context = _context;
+
 	if (typeof _parameters != 'undefined')
 	{
 		this.parameters = _parameters;
@@ -187,7 +196,9 @@ egw_json_request.prototype.sendRequest = function(_async, _callback, _sender)
 		data: request_obj,
 		dataType: 'json',
 		type: 'POST', 
-		success: this.handleResponse});
+		success: this.handleResponse,
+		error: function(_xmlhttp,_err) { alert('Ajax request to '+this.url+'?menuaction='+this.menuaction+' failed: '+_err); }
+	});
 }
 
 egw_json_request.prototype.alertFunc = function(_message, _details)
@@ -195,14 +206,24 @@ egw_json_request.prototype.alertFunc = function(_message, _details)
 	alert(_message);
 }
 
-function _egw_json_debug_log(_msg)
+function _egw_json_debug_log(_msg, _e)
 {
 	if (typeof console != "undefined" && typeof console.log != "undefined")
 	{
-		console.log(_msg);
+		console.log(_msg, _e);
 	}
 }
 
+/* Displays an json error message */
+egw_json_request.prototype.jsonError = function(_msg, _e)
+{
+	var msg = 'EGW JSON Error: '._msg;
+
+	//Log and show the error message
+	_egw_json_bebug_log(msg, _e);
+	this.alertHandler(msg);
+}
+
 /* Internal function which handles the response from the server */
 egw_json_request.prototype.handleResponse = function(data, textStatus, XMLHttpRequest)
 {
@@ -211,93 +232,152 @@ egw_json_request.prototype.handleResponse = function(data, textStatus, XMLHttpRe
 		var hasResponse = false;
 		for (var i = 0; i < data.response.length; i++)
 		{
-			var res = data.response[i];				
-
-			switch (data.response[i].type)
+			try
 			{
-				case 'alert':
-					//Check whether all needed parameters have been passed and call the alertHandler function
-					if ((typeof res.data.message != 'undefined') && 
-						(typeof res.data.details != 'undefined'))
-					{					
-						this.alertHandler(
-							res.data.message,
-							res.data.details)
-						hasResponse = true;
-					}
-					break;
-				case 'assign':
-					//Check whether all needed parameters have been passed and call the alertHandler function
-					if ((typeof res.data.id != 'undefined') && 
-						(typeof res.data.key != 'undefined') &&
-						(typeof res.data.value != 'undefined'))
-					{					
-						var obj = document.getElementById(res.data.id);
-						if (obj)
+				var res = data.response[i];				
+
+				switch (data.response[i].type)
+				{
+					case 'alert':
+						//Check whether all needed parameters have been passed and call the alertHandler function
+						if ((typeof res.data.message != 'undefined') && 
+							(typeof res.data.details != 'undefined'))
+						{					
+							this.alertHandler(
+								res.data.message,
+								res.data.details)
+							hasResponse = true;
+						} else
+							throw 'Invalid parameters';
+						break;
+					case 'assign':
+						//Check whether all needed parameters have been passed and call the alertHandler function
+						if ((typeof res.data.id != 'undefined') && 
+							(typeof res.data.key != 'undefined') &&
+							(typeof res.data.value != 'undefined'))
+						{					
+							var obj = document.getElementById(res.data.id);
+							if (obj)
+							{
+								obj[res.data.key] = res.data.value;
+								hasResponse = true;
+							}
+						} else
+							throw 'Invalid parameters';
+						break;
+					case 'data':
+						//Callback the caller in order to allow him to handle the data
+						if (this.callback)
 						{
-							obj[res.data.key] = res.data.value;
+							this.callback.call(this.sender, res.data);
 							hasResponse = true;
 						}
-					}
-					break;
-				case 'data':
-					//Callback the caller in order to allow him to handle the data
-					if (this.callback)
-					{
-						this.callback.call(this.sender, res.data);
-						hasResponse = true;
-					}
-					break;
-				case 'script':
-					if (typeof res.data == 'string')
-					{
-						try
+						break;
+					case 'script':
+						if (typeof res.data == 'string')
 						{
-							var func = function() {eval(res.data);};
-							func.call(window);
-						}
-						catch (e)
+							try
+							{
+								var func = function() {eval(res.data);};
+								func.call(window);
+							}
+							catch (e)
+							{
+								e.code = res.data;
+								_egw_json_debug_log(e);
+							}
+							hasResponse = true;
+						} else
+							throw 'Invalid parameters';
+						break;
+					case 'jquery':
+						if (typeof res.data.select == 'string' &&
+							typeof res.data.func == 'string')
 						{
-							e.code = res.data;
-							_egw_json_debug_log(e);
-						}
-						hasResponse = true;
-					}
-					break;
-				case 'jquery':
-					if (typeof res.data.select == 'string' &&
-					    typeof res.data.func == 'string')
-					{
-						try
+							try
+							{
+								var jQueryObject = $(res.data.select, this.context);
+								jQueryObject[res.data.func].apply(jQueryObject,	res.data.parms);
+							}
+							catch (e)
+							{
+								_egw_json_debug_log(e);
+							}
+							hasResponse = true;
+						} else
+							throw 'Invalid parameters';
+						break;
+					case 'redirect':
+						if (typeof res.data.url == 'string' &&
+							typeof res.data.global == 'boolean')
 						{
-							var jQueryObject = $(res.data.select);
-							jQueryObject[res.data.func].apply(jQueryObject,	res.data.parms);
-						}
-						catch (e)
-						{
-							_egw_json_debug_log(e);
-						}
-						hasResponse = true;
-					}
-					break;
-				case 'redirect':
-					if (typeof res.data.url == 'string' &&
-						typeof res.data.global == 'boolean')
-					{
-						//Special handling for framework reload
-						if (res.data.url.indexOf("?cd=10") > 0)
-							res.data.global = true;
+							//Special handling for framework reload
+							if (res.data.url.indexOf("?cd=10") > 0)
+								res.data.global = true;
 
-						if (res.data.global)
+							if (res.data.global)
+							{
+								egw_topWindow().location.href = res.data.url;
+							}
+							else
+							{
+								window.location.href = res.data.url;
+							}
+
+							hasResponse = true;
+						} else
+							throw 'Invalid parameters';
+						break;
+					case 'css':
+						if (typeof res.data == 'string')
 						{
-							egw_topWindow().location.href = res.data.url;
-						}
-						else
+							//Check whether the requested file had already be included
+							if (!egw_json_files[res.data])
+							{
+								egw_json_files[res.data] = true;
+
+								//Get the head node and append a new link node with the stylesheet url to it
+								var headID = document.getElementsByTagName('head')[0];
+								var cssnode = document.createElement('link');
+								cssnode.type = "text/css";
+								cssnode.rel = "stylesheet";
+								cssnode.href = res.data;
+								headID.appendChild(cssnode);
+							}
+							hasResponse = true;
+						} else
+							throw 'Invalid parameters';
+						break;
+					case 'js':
+						if (typeof res.data == 'string')
 						{
-							window.location.href = res.data.url;
-						}
-					}
-					break;
+							//Check whether the requested file had already be included
+							if (!egw_json_files[res.data])
+							{
+								egw_json_files[res.data] = true;
+
+								//Get the head node and append a new script node with the js file to it
+								var headID = document.getElementsByTagName('head')[0];
+								var scriptnode = document.createElement('script');
+								scriptnode.type = "text/javascript";
+								scriptnode.src = res.data;
+								headID.appendChild(scriptnode);
+							}
+							hasResponse = true;
+						} else
+							throw 'Invalid parameters';
+						break;
+					case 'error':
+						if (typeof res.data == 'string')
+						{
+							this.jsonError(res.data);
+							hasResponse = true;
+						} else
+							throw 'Invalid parameters';
+						break;
+				}
+			} catch(e) {
+				this.jsonError('Internal JSON handler error', e);
 			}
 		}
 
diff --git a/phpgwapi/js/jsapi/jsapi.js b/phpgwapi/js/jsapi/jsapi.js
index bfc3505515..b5d845eb9c 100644
--- a/phpgwapi/js/jsapi/jsapi.js
+++ b/phpgwapi/js/jsapi/jsapi.js
@@ -39,19 +39,53 @@ else if (document.layers)
 	is_ns4 = true;
 }
 
+/**
+ * Seperates all script tags from the given html code and returns the seperately
+ * @param object _html object that the html code from which the script should be seperated. The html code has to be stored in _html.html, the result js will be written to _html.js
+ */
+
+egw_seperateJavaScript = function(_html)
+{
+	var html = _html.html;
+	
+	var in_pos = html.search(/<script/im);
+	var out_pos = html.search(/<\/script>/im);
+	while (in_pos > -1 && out_pos > -1)
+	{
+		/*Seperate the whole <script...</script> tag */
+		var js_str = html.substring(in_pos, out_pos+9);
+
+		/*Remove the initial tag */
+		/*js_str = js_str.substring(js_str.search(/>/) + 1);*/
+		_html.js += js_str;
+
+		
+		html = html.substring(0, in_pos) + html.substring(out_pos + 9);
+
+		var in_pos = html.search(/<script/im);
+		var out_pos = html.search(/<\/script>/im);
+	}
+
+	_html.html = html;
+}
+
+
 /**
  * Returns the top window which contains the current egw_instance, even for popup windows
  */
 function egw_topWindow()
 {
-	if (window.opener)
+	if (typeof window.parent != "undefined" && typeof window.parent.top != "undefined")
+	{
+		return window.parent.top;
+	}
+
+	if (typeof window.opener != "undefined" && typeof window.opener.top != "undefined")
 	{
 		return window.opener.top;
 	}
-	else
-	{
-		return window.top;
-	}
+
+	return window.top;
 }
 
 /**