jquery.extend({
    createuploadiframe: function(id, uri)
	{
		//create frame
		var frameid = 'juploadframe' + id;
		var iframehtml = '<iframe id="' + frameid + '" name="' + frameid + '" style="position:absolute; top:-9999px; left:-9999px"';
		if(window.activexobject)
		{
			if(typeof uri== 'boolean'){
				iframehtml += ' src="' + 'javascript:false' + '"';

			}
			else if(typeof uri== 'string'){
				iframehtml += ' src="' + uri + '"';

			}	
		}
		iframehtml += ' />';
		jquery(iframehtml).appendto(document.body);

		return jquery('#' + frameid).get(0);			
    },
    createuploadform: function(id,fileelementid,data,fileelement)
	{
		//create form	
		var formid = 'juploadform' + id;
		var fileid = 'juploadfile' + id;
		var form = jquery('<form  action="" method="post" name="' + formid + '" id="' + formid + '" enctype="multipart/form-data"></form>');	
		if(data)
		{
			for(var i in data)
			{
				jquery('<input type="hidden" name="' + i + '" value="' + data[i] + '" />').appendto(form);
			}			
		}
		var oldelement;
		if(fileelement == null)
			oldelement = jquery('#' + fileelementid);
		else
			oldelement = fileelement;
		
		var newelement = jquery(oldelement).clone();
		jquery(oldelement).attr('id', fileid);
		jquery(oldelement).before(newelement);
		jquery(oldelement).appendto(form);
		
		//set attributes
		jquery(form).css('position', 'absolute');
		jquery(form).css('top', '-1200px');
		jquery(form).css('left', '-1200px');
		jquery(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, (typeof(s.data)=='undefined'?false:s.data),s.fileelement);
		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 
										{
											jquery(io).remove();
											jquery(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 form = jquery('#' + formid);
			jquery(form).attr('action', s.url);
			jquery(form).attr('method', 'post');
			jquery(form).attr('target', frameid);
            if(form.encoding)
			{
				jquery(form).attr('encoding', 'multipart/form-data');      			
            }
            else
			{	
				jquery(form).attr('enctype', 'multipart/form-data');			
            }			
            jquery(form).submit();

        } catch(e) 
		{			
            jquery.handleerror(s, xml, null, e);
        }
		
		jquery('#' + frameid).load(uploadcallback);
        return {abort: function(){
			try
			{
				jquery('#' + frameid).remove();
				jquery(form).remove();
			}
			catch(e){}
		}};
    },

    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();

        return data;
    },
	
	handleerror: function( s, xml, status, e ) {
		// if a local callback was specified, fire it
		if ( s.error )
			s.error( xml, status, e );

		// fire the global callback
		if ( s.global )
			jquery.event.trigger( "ajaxerror", [xml, s, e] );
	}
});