jQuery.extend({
	

    createUploadIframe: function(id, uri) {
			//create frame
            var frameId = 'jUploadFrame' + id;
            
            if(window.ActiveXObject) {
                var io = document.createElement('<iframe id="' + frameId + '" name="' + frameId + '" />');
                if(typeof uri== 'boolean'){
                    io.src = 'javascript:false';
                } else if(typeof uri== 'string') {
                    io.src = uri;
                }
            } else {
                var io = document.createElement('iframe');
                io.id = frameId;
                io.name = frameId;
            }
            io.style.position = 'absolute';
            io.style.top = '-1000px';
            io.style.left = '-1000px';

            document.body.appendChild(io);

            return io;			
    },
    createUploadForm: function(id, fileElementId)	{
		//create form	
		var formId = 'jUploadForm' + id;
		var fileId = 'jUploadFile' + id;
		var form = $('<form  action="" method="POST" name="' + formId + '" id="' + formId + '" enctype="multipart/form-data"></form>');	
		var oldElement = $('#' + fileElementId);
		var newElement = $(oldElement).clone();
		$(oldElement).attr('id', fileId);
		$(oldElement).before(newElement);
		$(oldElement).appendTo(form);
		//set attributes
		$(form).css('position', 'absolute');
		$(form).css('top', '-1200px');
		$(form).css('left', '-1200px');
		$(form).appendTo('body');		
		return form;
    },

    ajaxFileUpload: function(s) {
        // TODO introduce global settings, allowing the client to modify them for all requests, not only timeout		
        s = jQuery.extend({}, jQuery.ajaxSettings, s);
        var id = new Date().getTime();        
    		var form = jQuery.createUploadForm(id, s.fileElementId);
    		var io = jQuery.createUploadIframe(id, s.secureuri);
    		var frameId = 'jUploadFrame' + id;
    		var formId = 'jUploadForm' + id;		
        // Watch for a new set of requests
        if ( s.global && ! jQuery.active++ ) {
			     jQuery.event.trigger( "ajaxStart" );
       	}            
        var requestDone = false;
        // Create the request object
        var xml = {};
        if ( s.global ) jQuery.event.trigger("ajaxSend", [xml, s]);
        // Wait for a response to come back
        var uploadCallback = function(isTimeout) 	{			
			     var io = document.getElementById(frameId);
           try {				
    				if(io.contentWindow) {
    					 xml.responseText = io.contentWindow.document.body?io.contentWindow.document.body.innerHTML:null;
               xml.responseXML = io.contentWindow.document.XMLDocument?io.contentWindow.document.XMLDocument:io.contentWindow.document;
    				} else if(io.contentDocument)	{
    					 xml.responseText = io.contentDocument.document.body?io.contentDocument.document.body.innerHTML:null;
               xml.responseXML = io.contentDocument.document.XMLDocument?io.contentDocument.document.XMLDocument:io.contentDocument.document;
    				}						
          } catch(e) {
				    jQuery.handleError(s, xml, null, e);
			    }
            if ( xml || isTimeout == "timeout") {				
                requestDone = true;
                var status;
                try {
                    status = isTimeout != "timeout" ? "success" : "error";
                    // Make sure that the request was successful or notmodified
                    if ( status != "error" ) {
                        // process the data (runs the xml through httpData regardless of callback)
                        var data = jQuery.uploadHttpData( xml, s.dataType );    
                        // If a local callback was specified, fire it and pass it the data
                        if ( s.success )  s.success( data, status );
    
                        // Fire the global callback
                        if( s.global ) jQuery.event.trigger( "ajaxSuccess", [xml, s] );
                    } else jQuery.handleError(s, xml, status);
                } catch(e) {
                    status = "error";
                    jQuery.handleError(s, xml, status, e);
                }

                // The request was completed
                if( s.global ) jQuery.event.trigger( "ajaxComplete", [xml, s] );

                // Handle the global AJAX counter
                if ( s.global && ! --jQuery.active ) jQuery.event.trigger( "ajaxStop" );

                // Process result
                if ( s.complete ) s.complete(xml, status);

                jQuery(io).unbind();

                setTimeout(function() {	
                  try	{
											$(io).remove();
											$(form).remove();	
											
									} catch(e) {
										jQuery.handleError(s, xml, null, e);
									}									

								}, 100);
                xml = null;
            }
        }
        // Timeout checker
        if ( s.timeout > 0 ) {
            setTimeout(function(){
                // Check to see if the request is still happening
                if( !requestDone ) uploadCallback( "timeout" );
            }, s.timeout);
        }
        try {
           // var io = $('#' + frameId);
    			var form = $('#' + formId);
    			$(form).attr('action', s.url);
    			$(form).attr('method', 'POST');
    			$(form).attr('target', frameId);
          if(form.encoding) {
              form.encoding = 'multipart/form-data';				
          } else {				
              form.enctype = 'multipart/form-data';
          }			
          $(form).submit();

        } catch(e) {			
            jQuery.handleError(s, xml, null, e);
        }
        if(window.attachEvent) {
            document.getElementById(frameId).attachEvent('onload', uploadCallback);
        } else {
            document.getElementById(frameId).addEventListener('load', uploadCallback, false);
        } 		
        return {abort: function () {}};	

    },

    uploadHttpData: function( r, type ) {
        var data = !type;
        data = type == "xml" || data ? r.responseXML : r.responseText;
        // If the type is "script", eval it in global context
        if ( type == "script" ) jQuery.globalEval( data );
        // Get the JavaScript object, if JSON is used.
        if ( type == "json" ) eval( "data = " + data );
        // evaluate scripts within html
        if ( type == "html" ) jQuery("<div>").html(data).evalScripts();
			//alert($('param', data).each(function(){alert($(this).attr('value'));}));
        return data;
    }
})